Troy Rail Covers are engineered to survive the most extreme conditions. Constructed from durable, heat & chemical resistant synthetic polymer resin, the Troy Rail Cover quickly and easily slides onto a 1913 Picatinny Rail and locks into place with a built-in retaining clip. Scientifically engineered and proven to reduce heat transfer and abrasions to the operator's hand. No tools required. Package includes two 1.7, two 2.6, two 3.5, two 4.4, two 5.3 and two 6.2.Made in the U.S.A.