Flush QD Mount for plastic stocks or handguards. Steel QD mount and nut, low-profile, 4 Position, rotation limited, can be mounted in most hollow plastic stocks and uses standard QD swivel (not included). Weight: 0.3 ounces. Flush QD Mount can be installed in most plastic stocks that are hollow and handguards that have a relatively flat section. Installation requirements: 1/2 inch hole must be drilled, material thickness of less than 1/4 inch, 5/8 inch wrench, QD swivel. Permanent thread locker is recommended. Black.