Several military units including the US Special Forces, Israeli Commandos, British SAS, and some Taiwan Police Agencies have used the Ingram MAC10. The barrel is threaded for a suppressor/silencer giving the weapon a good deal of versatility in it application in Counter Terrorist operations as well as VIP protection. This is a spring gun and the slide must be cocked for each shot. It requires no gas or batteries to operate. Due to this feature, the costs of spring guns are significantly lower, as well as maintenance. They are the most durable of all airsoft guns because they have less pieces that can break. Spring guns are very reliable, affordable and handsome guns.