A quick look at the ASG STI Duty One CO2 Blowback Pistol which should be available at ASG authorised sellers... "The DUTY ONE is fully licensed by the famous high-end small arms manufacturer, STI® International, based in Texas, USA. The pistol is semi-automatic Gas blow-back and based on the classic model 1911 but STI has upgraded and changed the design and many of the functions. The frame has an integrated front waiver rail for mounting light and laser. The grip is marked with STI logo and the high rise beavertail grip secures a perfect hold on the pistol. The BB’s are stored in the drop-out magazine and powered by a 12g Co2 capsule which is cleverly kept away in the pistol grip thanks to the easy load system. The pistol has a unique serial number and the metal slide has the authentic STI logo engraved. The STI DUTY ONE comes in two versions – a non-blowback and a blowback version."