These locking power cords are ideal for powering your high voltage/ high current equipment. On one end, the plug connects to a Locking NEMA L6-30R wall outlet or receptacle, while the other end connects to equipment that uses the Locking NEMA L6-30P, meaning this counts as a heavy duty extension cord. Additionally, this power cord features the twist-lock plug and receptacle which rotate to lock into their matching configurations.