The bbx11 is a blowback.177 caliber bb gun powered by a 12 gram co2 capsule.Both bbs and the co2 are housed in the drop-free full size magazine.With a skeletonized trigger and hammer, the blowback action bbx11 is pure fun on the range.Bbs will fly at 410 fps.You will definitly want to pick up a spare magazine or two to keep the bbs flying.The bbx11 is powered by a single 12g non-threaded co cartridge (purchased separately).Action: Semi-AutoCaliber: 177Capacity: 16rdSights: Fiber Optic Front & Rear