This Scopecoat fits all 3.5x ACOG scopes except for models with RMR sights. The Scopecoat is constructed of the highest quality neoprene laminated with nylon. Its simple design safeguards the scope or sighting system from dings and scratches, dust, dirt, and moisture. Neoprene has a 5% moisture absorbency which takes moisture (condensation and sweating) away from the scope or sight and helps protect it. The nylon shields against the elements. Simply stretch both ends over your scope or sight. The recommended fit is either "relaxed same length" or slightly stretched.