The Rubber O-Ring 4 Pack has just about every convenient size that you will need for your strap-on harness and for any strap-on harness compatible dildo. The smallest O-ring is 1.25" (3.2xm), perfect for if you have a really slim and miniature dildo. The medium size is 1.5"(3.8 cm), which I found had the most perfect grip and hold for my thicker strap on dildos without it being too tight nor too loose. The large size is 1.75" (4.5cm), very suitable for much larger, thicker, and wider based strap on dildos. The XL size is 2"(5cm), great for a much beefier strap on dong.

I used the Bionic harness to test out these O-rings. For this particular harness, I found that the smallest O-ring was a tighter fit to snap into place, and it wasn't compatible for the strap on dildos I had, but I'm sure if I had a smaller sized one it would have fit into place just fine. The medium size O-ring was the perfect fit for all of my strap on dildos, so I would say if there was one O-ring that you can leave in your harness to use for most strap on dildos, it is the medium sized O-ring. The large O-ring is great for when you have a much thicker dong that needs a little extra room to fit comfortably, and the XL is better for those dildos that are either much bigger or have a wider base. With each dildo that did fit with these O-rings, I loved that none of my dildos felt loose, floppy, or flimsy in the harness. They were held tight, and made a strap on sex session worry-free.

Purchasing this set is a good investment. It's relatively inexpensive. The sizes range to fit many sized dildos and you can easily store it in a plastic bag and in a cool place. Cleaning them only requires a light rinse of water and soap. Rubber, however, may not be as everlasting as steel O-rings, but if you take care of these well, these set of O-rings can last for years.

The best thing about this set: it's easy to travel with! Have it with you for sex parties, vacations, or for a quiet and kinky evening. It's a must-have for all of your strap on harness/strap on sex needs. Get yourself a pack, and you won't find yourself having to purchase other O-rings again.