Features of the HK45 Gas Airsoft Pistol: Real HK45 pistol chambered in .45 ACP. Fully licensed pistol with correct markings. Comes with additional backstrap Metallic upper with a polymer frame. Can adjust hop without removing slide and using a key. Tri Dot affair. 16mm CCW thread. Functional de-cocker. For sale in Asia HK45 Compact Tactical Part Diagram Specifications of the HK45 Gas Airsoft Pistol: Length - 202mm Weight - 795g Magazine Capacity - 20 Rounds Power Source - Green Gas Blowback - Yes Shooting Modes - Semi Only Hop-up - Adjustable by using a key Magazine Compatibility - Umarex (VFC) HK45 Compact Tactical 20rds Gas Magazine FPS - 320 This product is only compatible with gas designed specifically for Airsoft guns. Do not use lighter fluid or butane gas, as that will cause permanent damage.