The WE Hi-Capa 5.1 K is a solid green gas airsoft pistol with an excellent blowback kick. This pistol has a functional full metal slide with black grips and is comfortable to hold and fire. The gun features a working hammer, a 30 rd magazine, and a shot velocity of 328 fps (using.20g BBs). An adjustable hop-up unit also lets you fine tune the accuracy of the gun for long distance shooting. This is a great sidearm choice for airsoft skirmishes. Features: Semi-automatic Full metal slide Adjustable hop-up Working hammer Velocities for propane and green gas are 290-310 fps using .20g BBs. The pistol is compatible with propane and green gas. Propane adapter & green gas are not included. The gun does not have a threaded muzzle, although it is shown with one in the images.