Easily convert your existing UDP-9 or AR-9 pistol to a full size rifle. Kit includes 16" 9mm barrel, 15" handguard, mounting hardware and B5 Bravo Stock. Ready to install on any mil-spec upper receiver. Compatible with both GLOCK(R) and COLT(R) style 9mm magazines. Please note the conversion kits now come with a 1/2x36 9MM barrel. Features: 16? 9mm barrel made from 4150 chrome-moly steel with a 1-10" twist rate. 1/2x36 TPI 15" ultralight handguard with M-LOK(R) mounting interface on the 3, 6, 9 & 12 O'clock positions Top mil-spec 1913 picatinny rail with lightening cut B5 Bravo Rifle Stock (black color) Compatible with both GLOCK(R) and COLT(R) style 9mm dedicated lower receivers. Caliber: 9mm NATO