The SADLAK Front Rail Mounting System is designed for clamp-on type bi-pods and accessories with a QD Post to attach Harris bi-pods while retaining yourstock sling swivel.Steel Models uses unique internal Oval Nut plates specifically designed to fit the contour of four popular M14/M1A stocks. Once the nut plate is installed the rail can be installed or removed without rifle disassembly using two external screws through counter bored holes in the rail.