Ncstar MM1 M-1 Carbine Rifle Scope Mount is Easy too install without altering your M-1 carbine rifle. This M1 Carbine Scope Mount Is Weaver style mount base it allows you to mount a scope, tactical light or laser, length 3.5". (Installs in rear sight dovetail ) so you must remove the existing rear sight by moving it out to the right side of the weapon if you are not skilled it might require a gunsmith. LIMITED LIFETIME WARRANTY. This M-1 scope mount is great it lets you mount a scope quick and easy.