Type: BB air pistol. Manufacturer: ASG. Model: ASG STI Duty One 1911 Non Blowback. Materials: Metal slide and polymer frame. Weight: 1.8 pounds. Barrel: Metal non-rifled. Propulsion: CO2 x 1. Action: Semi auto blowback, single action. Ammunition Type: 4.5mm BB's. Ammunition Capacity: 20 round magazine. FPS: 407. In terms of comparing the Non Blowback version of the ASG STI Duty One 1911 to the Blowback version without actually shooting it, they are pretty much identical except for the double and single action trigger found on the Non Blowback version. Even the slide seems to work the same. The big difference will be when I shoot the Non Blowback ASG STI Duty One. Will it shoot with a lot more FPS and will the reduced slide movement give it more accuracy? I am assuming yes to both of these question but I guess we will all have to wait and see when I do my official Shooting Field Test Comparison... Read full article here: https://www.replicaairguns.com/2014/9/27/asg-sti-duty-one-1911-non-blowback-co2-bb-gun-table-top-revi.html Buy the STI Duty One NBB in Canada: https://www.replicaairguns.ca/asg-co2-4-5mm-sti-duty-one-air-pistol Buy the STI Duty One NBB in the US: https://www.replicaairguns.us/asg-co2-4-5mm-sti-duty-one-air-pistol