Measure the widest part of your toy. Pick an O-ring slightly larger than that number. Never the same size, never smaller.
That's the rule. The rest of this is what to do when your toy and your ring don't line up.
Our O-ring sizes
We make four: 1.5", 1.65", 1.75", and 2.0".
Every product page lists which ring that style has. Check there rather than assuming, because colorways within the same style don't always share a ring size.
The trap: an exact match
A 1.75" toy and a 1.75" ring sounds perfect. It isn't. That's a tight fit, and tight is the thing to avoid. Go up to the next ring size.
If your toy is narrower than your ring
Add a Stabilizer Insert. It fills the gap so the toy sits secure, and it keeps a loose toy from sagging and dragging on the front panel.
Two versions, not interchangeable. One is cut for Brief+, Panty, and Biker. The other is cut for Boxer and High Rise. Match it to the harness you own, not to the toy.
To use it: slide the stabilizer in behind the O-ring, then push the toy through both together as one unit.
If you own several toys in different diameters, one stabilizer is a lot cheaper than a harness per toy.
If your toy is wider than your ring
Size up to a wider ring. Don't force it.
Why the rule exists
Force silicone through a gap that won't give and one of two things happens. The ring tears through the fabric around it, or, with softer silicone, the squeeze and the rubbing tear the toy.
Neither is dramatic. It's gradual, it looks like ordinary wear, and most people never trace it back to a ring that was a hair too small.
Why our O-rings don't stretch
You'll see stretchable elastic O-rings on other harnesses, advertised as fitting toys of any shape and size. One harness, every toy, no measuring. It sounds like flexibility.
What it is, is squeeze. An elastic ring holds a toy by constant compression, and constant compression on softer silicone is precisely how softer silicone gets damaged. The stretch being sold as convenience is the same stretch slowly chewing on your toy.
So ours are fixed, in a range of sizes. You have to know your toy's diameter, which is one more thing to check. In exchange, your toy is held rather than gripped, and it lasts longer.
The 2.0" is a different pattern
Our 2.0" styles aren't the same garment with a wider ring punched into it. We redrew the pattern. The waistband drops lower, closer to the O-ring, and it's a 2.5" band instead of the 1.75" band used elsewhere.
Wider band, sitting closer to the load. A bigger toy puts more leverage on the front of the garment, and a standard band higher up doesn't counter that as well.
Two rings: pack low, play high
Duo styles have two O-rings stacked on the front panel, and the second one does more than give you options.
Run the shaft through the lower ring and your toy sits down between your legs, packed and out of the way. Move it up to the upper ring for play. One garment, both jobs, no changing in between.
Works with any toy that fits a 1.65" ring or smaller. You can also run two toys at once.
Look for Duo in the name if that's what you want: Duo Brief+, Duo Panty+, Duo Boxer+. The + on its own means something different, double layer, the two-pairs-of-underwear-in-one construction. So a Brief+ is not automatically a Duo.
Bringing your own toy
Check that it's labeled harness compatible: a flat, stable base built to sit against a ring, rather than a suction cup or a base made to stand on its own. A toy without one can work loose no matter how well the diameter matches.
Sharing
Using a harness and toy with a partner, or switching between partners? Clean toys per the manufacturer's instructions between uses, and consider condoms on toys when sharing or switching between different kinds of penetration.
The short version
- Measure the widest part of the shaft.
- Pick a ring slightly larger. Never equal, never smaller.
- Exactly the same as a ring size? Go up one.
- Narrower than your ring? Stabilizer Insert, cut for your style.
- Wider than your ring? Size up, don't force it.
- Want to pack and play in one garment? Duo, with a toy 1.65" or under.
Back to the full buying guide, or the sizing guide for your waist size.
J / RodeoH