The ES-68 is a locking bayonet hood designed for the Canon 50mm f/1.8 STM. It offers protection from glare, raindrops and the occasional stray doggie nose. The lock prevents the hood from working loose due to rubbing or light whacks. Fit and finish are excellent: quality plastic, fingerprint resistant matte black exterior and flat black interior to nix reflections (paint, not rayon flocking). Plus, the exterior finish is perfectly matched to the EF 50 1.8 STM lens. The hood can be reverse mounted on the lens for compact storage.