The BlackTravelCoat for the Canon 600mm f/4 IS II Lens from LensCoat is a 3.0mm thick shock-absorbing closed-cell neoprene lens cover that is custom tailored to fit the lens with its lens hood mounted in reverse position. It is designed to fully protect the lens from bumps, scratches and abrasions when not in use, without the need of a more traditional bulky lens case. The trim fit of the coat permits you to have extra storage space when you're packing for that long photo excursion - or even a day trip. The coat simply slides over the lens, and closes with a secure touch fastener. The black TravelCoat renders the lens dark when shooting in low light scenarios Use with the appropriate optional Hoodie for complete lens protection.