Product Description A.R.M.S. 74 Extension Cantilever Extension for #74 Mt. for Comp M4. Fits in between Comp M4 and 74 Throw Lever Mount to give you 1/2a ^2 height. 100% MADE IN THE USA. ARMS 74EXT Extension at BOTACH $35.00 Buy Now Check Price on Amazon Check Price on eBay