When paired with a Tandemkross Compensator, like the name states, these O‑rings earn a 5‑star rating. I have them paired with the game changer pro compensator on my Tippmann M4‑22 Elite and my RCR and they work great in that role. The challenge comes when timing other muzzle brakes/compensators and some flash hiders on other AR platforms. Normally, you’re stuck stacking multiple shims to get proper alignment—which gets costly fast. The alternative is a crush washer, but all the stars in the galaxy would need to align if you think your brake will also. Or you have a crush washer, jam nut, shim kit combination and that’s technically not the correct way to do it. That’s why I decided to try a few 3‑packs of the Tandemkross O‑rings. I’ve purchased every nitrile and Viton Orings from harbor freight, Menards, hardware stores, but none matched the Tandemkross specs it seemed. Other O‑rings I tried would squeeze out the sides under torque, while the Tandemkross ones felt thicker and denser. Unfortunately, once I started using them on my other AR’s, they also squeezed out the sides. Back to shims it is.

I have two orders with your company and was pleased with items and speed of delivery.

ken.kraft@tds.net

Good to have extras

good to have some spares on hand shipping was great.

They are amazing

But I needed to use 2 to get them to fit 1 of my 2 FN 5.7 pistols.

Got to have extras just in case

Great product. Great service.