The Glock 20 is the 10mm Auto, full-size variant of the more iconic Glock 17 9x19mm, full-size pistol. It was first brought to market in 1991 due to the growing-at-the-time 10mm Auto cartridge becoming popular among LEOs and security companies. Due to the longer cartridge and higher pressures, the pistol is slightly larger than the Glock 17, having a roughly 2.5mm greater width and 7mm greater length. PROPERTY OF C.AI ARMORY