Umarex P2P HDP 50 Gen 2 Compact Pistol .50 Caliber Orange w Pepper RoundsUmarex P2P HDP 50 Gen 2 Compact w Pepperballs The Umarex P2P HDP 50 Gen 2 Compact is a . 50 caliber CO2 powered personal defense device. Gen2 upgrades include: higher velocity, textured grip, and the Gen 2 quick pierce system. The HDP 50 Compact is designed for snag free ergonomic performance and quick deployment so you can put distance between yourself and a threat. The 8 gram CO2 cartridge is instantly activated with a firm tap of the Gen 2 Quick