Troy Rail Covers easily slide onto a MIL-STD Picatinny Rail and locks into place with a built-in retaining clip and can be adjusted with a bullet tip; no tools required. Constructed from durable, heat and chemical-resistant synthetic polymer resin, each rail cover is scientifically engineered and proven to reduce heat transfer and hand abrasions. The Troy Rail Cover Package is a 12 piece set including: two 1.7?, two 2.6?, two 3.5?, two 4.4?, two 5.3? and two 6.2? covers. Patent Pending.