Colt ar 15. It is built on a SP-1 lower made in 1974. It is in M4 configuration with the a3 weaver rails upper. It has a 16 inch heavy barrel with the bayonet log, flash hider, and a colt three position collaspable stock. It is in excellent shape and is a great shooter. Ihad the carrying handle for it also. I am asking $1250 delivered to your ffl.