Leviton's Black & White 50 A, Non-NEMA line of industrial-grade locking blade devices feature rugged construction that resists impact, sunlight, chemicals and rough use. All contacts and blades are solid one-piece construction for superior conductivity. Corrosion resistant versions feature nickel-plated contacts and blades, plus stainless steel shrouds and screws. The ergonomic, fluted-body design with radial gripping edge is ideal for gripping and pulling. The unique cord clamp accepts a wide range of cord sizes, providing a secure grip without damaging the cord. And they are backed by a limited lifetime warranty.