Hollow butt plugs, sometimes called tunnel plugs, are a distinct category of anal toy with an open channel running through the center — giving them capabilities no solid plug can match. If you’ve seen these online and wondered what they’re actually for, this guide breaks down the use cases, the safest materials, and the top picks worth considering in 2026.
Part 1. What Is a Hollow Butt Plug?
A hollow butt plug is an anal toy that features a cylindrical or tapered outer shape with a hollow tube running through the center from base to tip. Unlike a traditional solid plug that simply fills and stretches the anal canal, the open tunnel creates direct access through the plug once it’s inserted.
This design originated primarily in kink and BDSM communities, where the open channel enables a range of activities — from lube injection and digital access to visual play and penetration through the tunnel itself. The category is also used in anal training contexts, where the visual feedback and progressive stretching can be part of the practice.
🗣️ r/sextoys user: “The hollow design opens up a world of exploration — you can be penetrated, fisted, lubed up, and more. Unlike traditional plugs, the hollow core allows for additional stimulation.”
The term “tunnel plug” is used interchangeably with “hollow butt plug” across most retailers and communities. Some designs are completely see-through (using clear acrylic or TPR), while others use opaque silicone. The outer wall is typically 0.25–0.5 inches thick, meaning the insertable diameter is larger than what the tunnel opening alone suggests.
Part 2. Who Should (and Shouldn’t) Use a Hollow Plug
Hollow plugs are generally recommended for intermediate to advanced anal play practitioners. The outer wall of a hollow plug creates more stretch than a solid plug of the same listed diameter, because the hollow design means the anal sphincter must accommodate the full outer circumference rather than a solid core.
If you’ve only just begun exploring anal play, a solid beginner plug is usually the better starting point. Hollow plugs become more suitable once you’re comfortable with insertion and have some experience with gradual size progression.
Common use cases for hollow plugs include:
- Progressive anal stretching and training
- Kink and BDSM scenes involving access or visual elements
- Extended wear during partnered activity
- Hands-free lube application through the tunnel
People who should approach hollow plugs with caution — or avoid them until consulting a healthcare provider — include those with active anal fissures, hemorrhoids, or inflammatory bowel conditions. The hollow design can put different pressure on the rectal walls than a solid plug.
Part 3. The Best Hollow Butt Plugs: Top Picks Compared
When evaluating hollow plugs, the two most important measurements are outer diameter (how much stretch is required for insertion) and tunnel diameter (the usable opening once inserted). Material and wall thickness round out the selection criteria.
| Product | Material | Outer Diameter | Tunnel Diameter | Best For | Price Range |
|---|---|---|---|---|---|
| Oxballs Pig-Hole XL | TPR (phthalate-free) | 2.25″ | 1.25″ | Advanced users, kink play | $30–$45 |
| PerfectFit Tunnel Plug (M) | SilaSkin (TPR/silicone blend) | 1.75″ | 1.0″ | Beginners to intermediate, see-through | $20–$30 |
| Doc Johnson The Stretch | Platinum silicone | 2.0″ | 1.0″ | Silicone purists, hygiene-focused | $35–$50 |
| Master Series Peephole | ABS + silicone | 1.5″ | 0.75″ | Partner play, visual/kink scenes | $25–$35 |
| Fort Troff Meat Grinder | Silicone | 2.5″ | 1.5″ | Experienced users, maximum stretch | $45–$65 |
Oxballs Pig-Hole XL is the most frequently cited recommendation in community discussions for advanced users. Its phthalate-free TPR construction is softer and more flexible than rigid designs, which many find more comfortable for longer wear. Note that TPR is porous, so sterilization between users is not possible — it’s best treated as a single-user toy.
PerfectFit Tunnel Plug uses a SilaSkin blend that sits between silicone and TPR in softness. The clear design is popular for visual play and lets users easily monitor fit. It comes in three sizes (S/M/L), making it a sensible starting point for those new to hollow plugs.
Doc Johnson The Stretch stands out as the best fully non-porous option in this range. Platinum silicone means it can be sterilized by boiling, making it a good choice if hygiene is the top priority.
🗣️ r/sextoys user: “Oxballs Pig Holes are focused on body safety, contain no phthalates, and offer maximum comfort. The hollow core allows for a range of possibilities.”
Master Series Peephole is a smaller, more compact option suited to those whose primary interest is the visual or partner-access element rather than maximum stretch. The lower price point also makes it a lower-risk entry.
Part 4. Materials Guide: What to Look For in a Hollow Plug
Material selection matters more for hollow plugs than for solid plugs. A solid plug’s surface touches the rectal walls, but the entire inner tunnel of a hollow plug is continuously in direct contact with internal tissue — meaning any degraded or porous surface has more extended exposure.
| Material | Body-Safety | Cleanability | Temperature Play | Price Level |
|---|---|---|---|---|
| Silicone (platinum-grade) | Excellent | Boilable, bleachable | Limited (mild) | Medium–High |
| TPE / TPR | Variable (porous) | Surface wash only | Not recommended | Low–Medium |
| Hard Acrylic / Resin | Good (non-porous) | Easy to clean | Not recommended (brittle) | Low–Medium |
| Borosilicate Glass | Excellent (non-porous) | Boilable | Excellent | Medium–High |
Silicone is the safest mainstream choice for hollow plugs. Platinum-grade or medical-grade silicone is non-porous, non-reactive, and can be sterilized by boiling for 3–5 minutes. The main limitation is that silicone hollow plugs are typically less flexible than TPR alternatives, which can affect comfort during insertion.
TPE and TPR are the most common materials in affordable hollow plugs. They are softer and more flexible, but their porous surface structure means bacteria can survive cleaning. For hollow plugs used by a single person and cleaned carefully, this is a manageable risk — but they should never be shared.
Hard acrylic or resin hollow plugs (often clear) are non-porous and easy to wipe clean. They are rigid, which some users find comfortable and others find harsh — individual preference varies. They cannot tolerate temperature extremes.
Part 5. How to Use and Clean a Hollow Butt Plug
Preparation is the same as for any anal toy, with a few additions specific to the hollow design. Use a generous amount of water-based lubricant on both the outer surface and the inner tunnel before insertion. Warming up with a smaller solid plug can help relax the sphincter before introducing the larger outer diameter of a hollow plug.
Insertion should be slow and deliberate. Breathe out gently as you apply inward pressure — exhaling relaxes the anal sphincter and makes insertion easier. Once the widest outer point has passed the sphincter, the plug typically seats itself. You should feel the outer rim or flange resting against the exterior.
During use, the open tunnel allows for a range of activities depending on your intent:
- Inserting a lubrication syringe to coat internal tissue
- Allowing visual access for a partner
- Penetration through the tunnel (check manufacturer’s tunnel diameter before attempting)
- Finger insertion for manual stimulation
Wear duration: most guides suggest limiting hollow plug wear to sessions under 30 minutes for beginners, and checking in with comfort every 15 minutes. Extended wear beyond 60–90 minutes is typically for experienced users who have built up to it gradually.
Cleaning a hollow plug requires more attention than a solid toy:
- Remove the plug and immediately run warm water through the tunnel from both ends.
- Apply a mild, fragrance-free soap to the outer surface and inside the tunnel using your finger or a small brush.
- Rinse thoroughly — residue inside the tunnel is harder to detect than on a solid surface.
- For platinum silicone plugs only: boil in water for 3–5 minutes to sterilize fully.
- Air dry completely before storing — moisture in the tunnel can promote bacterial growth.
Store hollow plugs in a breathable pouch, separate from other silicone toys. Silicone-on-silicone contact can cause surface degradation over time.
Part 6. Exploring Adjustable Alternatives with OopXlab
OopXlab is a body-safe intimate wellness brand focused on design-forward toys made with medical-grade materials. While OopXlab does not currently carry a dedicated hollow or tunnel plug, two products in the lineup may appeal to those drawn to the adjustable and progressive aspects of hollow plug use.
The Inflatable Vibrating Butt Plug allows you to start small and gradually increase the diameter by inflating the plug — giving you control over your own pace of size progression without committing to a fixed-diameter toy from the start. This makes it a practical alternative for those interested in the stretching and training aspect of hollow plug use.
For those who read this guide and decide a solid plug suits them better, the Anal Plug from OopXlab offers a beginner-appropriate silicone option with a tapered shape for comfortable insertion and a stable base for safety. Both are made with body-safe materials and designed with the user’s comfort in mind.
FAQ
What is a hollow butt plug used for?
Hollow butt plugs are used for anal training and stretching, kink and BDSM scenes involving visual or physical access through the plug, and extended wear play. The open tunnel allows for lube injection, partner access, and other activities that a solid plug cannot facilitate.
What is the difference between a hollow plug and a regular butt plug?
A regular butt plug is solid and fills the anal canal for a feeling of fullness. A hollow plug has an open channel through the center, which allows access, visual play, and other activities during wear. Hollow plugs typically require more stretch to insert because the outer wall must pass the sphincter at full diameter.
Are hollow butt plugs safe for beginners?
They are generally not recommended as a starting point. Hollow plugs require the sphincter to stretch around the full outer diameter — which tends to be larger than beginner solid plugs. Most users find hollow plugs more appropriate after they have experience with standard anal toys and progressive sizing.
What is the best material for a hollow butt plug?
Platinum-grade silicone is generally considered the safest choice due to its non-porous surface, which can be fully sterilized by boiling. Borosilicate glass is an excellent premium option. TPE and TPR are softer and more affordable but porous — acceptable for single-user scenarios but cannot be shared or fully sterilized.
Can you wear a hollow butt plug during sex?
Yes, in many cases that is specifically one of the intended uses. The tunnel opening allows a partner to penetrate through the plug, or for manual stimulation during other sexual activity. Check the tunnel diameter specification to ensure it accommodates your intended use.
How do you clean a hollow butt plug?
Flush the tunnel with warm water immediately after use. Wash with mild soap inside and out, rinse thoroughly, and air dry completely. For platinum silicone models, boiling for 3–5 minutes provides full sterilization. Do not boil TPE or TPR materials — heat will degrade them.
What size hollow plug should I start with?
If you’re new to hollow plugs, look for an outer diameter under 1.75 inches and a wall thickness that allows a comfortable tunnel without excessive stretch. The PerfectFit Tunnel Plug in Small (outer diameter ~1.5″) is a commonly cited starting point. Always prioritize outer diameter over tunnel size when choosing your first hollow plug.