All USPs feature a fiber-reinforced polymer frame stiffened by stainless steel inserts at areas subject to stress and friction. Using a modified Browning-type action with a special patented recoil reduction system, the USP recoil reduction system reduces recoil effects on pistol components and also lowers the recoil forces felt by the shooter. The USP recoil reduction system is insensitive to ammunition types and requires no special adjustment or maintenance. Variant 1 is double action/single action with SAFE position; control lever (manual safety/decocking lever) is mounted on left side of the frame.