This is a Trijicon Mount known as the Ruggedized Miniature Reflex, model RM44.
Made from steel" replaces rear sight to allow the mounting of any Trijicon RMR/SRO. Fits all Glock(R) models (not including Glock(R) MOS slides).
Features:
Includes mount with dovetail base sealing plate optic screws and mount screws
