The Salmon River Solutions family of Arca rails are not only the lightest Arca rails on the market, they are also the only Arca rails available that match well to a rounded style hunting stock. Made from 7075 aluminum, SRS was able to design an incredibly light, but tough rail at only .55 oz. These work in Arca Swiss style tripod heads. They are 1.7" OAL, and has a slot for bolt spacing up to 1.2". Each rail comes with 10-32 screws and M-Lok mounting hardware, to provide compatibilty with a wide range of forends.