Glock 17 Gen5 Half Blowback .177 BB Gun .177 caliber CO2 powered Half blowback Muzzle velocity: 370 FPS Optics compatible Metal slide Polymer frame Overall length: 7.75" Barrel length: 4.5" Weight: .93 lbs 18-round BB capacity Compatible with Umarex Optic Adapter Plates for Glock Type MOS 1 and Umarex RDS 8 red dot sight Combo Includes: Glock 17 Gen5 MOS Half Blowback, 18 round magazine, and RDS 8 Red Dot optic