The Tally Picatinny Rail is a two piece machined aluminum base that easily mounts onto your modular quad rail system. The two base halves are connected with flexible shims, giving you enough flexibility to use the full range of equipment that can be mounted to a Talley rail system. The shims are placed just inside the rail, giving you enough space to install a red dot sight, holographic, or other optical device. When you remove the scopes, the red dot goes away, so you can enjoy your shooting sport without having to realign the scope. Talley bases can be installed almost anywhere a picatinny rail is bolted to the top rail. That means you can use them on and more. The Talley Picatinny Rail base only weighs 3 ounces, so you can mount it anywhere. This low profile design allows you to mount the scope close to the bore, giving you more flexibility with mounting.image