Rail Adapter HK USP This adapter converts the H&K USP Rail System On Compact Size Pistols to standard Weaver / Picatinny Rail for Laser Sight / Tactical Light Installation on the factory frame without gunsmithing. Installs in minutes Adapter is machined from Strong T6 aircraft-grade aluminum using modern CNC machinery. Comes in Swat Black mil spec. Much better then plastic adapters. This model fits the Compact HK USP Rails.