I purchased mine from Slide Fire. It has a switch on the stock that allows it to freefloat or lock in place. I have not used it yet on my 15-22 due to the suggested trigger group being as hard to find as magazines. I also have 3 MOE rifles which require the removal of the QD sling mount which kinda defeats the purpose of why I bought the MOE rifle. I'll eventually use the Slide Fire if I purchase a non MOE rifle - otherwise it will go on one of my Bushmasters.