One pair (qty 2) of retention o-rings for our weapon light covers and laser cover. These are the same equipement that our products originally ship with, which are a higher grade of material than the ones you typically find available in hardware or plumbing/hydraulic supply stores.
We have tested these extensively with our equipment and have found them to be of a higer quality and lifespan. They tend to not lose their stretch as easily, and on the largest covers will rebound without being loose after the cap has been left open for extended periods of time (weeks). They are also rated for better UV resistance, and higher temperature exposure.
