Hk Licensed Airsoft Ump 45 Full Metal Gearbox Aeg Cqb Submachine GunSPECIFICATIONS: OPERATION: ELECTRIC AUTOMATIC BUILD BODY: ULTRA DURABLE FIBER POLYMER BODY WITH FULL METAL INTERNALS FIRING MODES: SEMI AUTOMATIC AND FULL AUTOMATIC GEARBOX: FULL METAL VERSION 3, W EASY ACCESS QUICK SPRING CHANGE FEATURE OVERALL LENGTH = 27. 5" (STOCK EXTENDED); 18" (STOCK FOLDED) INNER BARREL LENGTH = 205MM MAGAZINE CAPACITY = 400 ROUNDS HI CAP MAGAZINE INCLUDED CALIBER = 6MM AIRSOFT BB VELOCITY = 310 330+ FPS WITH 0. 20 GRAM BBS