Made of premium high-strength, heat-resistant polymer with stainless steel hardware, this Front Lens Cap from Bioluminous is a snap-on black lens cap with black locking grips made specifically for the Canon EF 400mm f/4 lens SO (Diffraction Optics). The lens cap construction is rugged and durable, and the spring-loaded release tabs are designed to be large enough so that you mount and remove the lens cap while wearing gloves. The cap is a snug fit on your lens and can be mounted on the lens without, or with the lens hood attached, even if the hood is attached reversed.
UPC: 850061985262