Do not purchase this lens from this seller! After receiving it in a white box with a Canon sticker on it I got suspicious- contacted Canon in Europe, who were extremely helpful, and after sending them photographs of everything they confirmed that yes this is a genuine lense but made as a parallel product and not for public market. This means the warranty IS NOT VALID, and they CANNOT guarantee it works at all.
I’ve contacted Amazon for a return and explained everything to them but unfortunately this seller is still here. I recommend buying this lense at a proper place (I got it for £1,019 in a camera shop) and Canon have a £110 cashback promotion so it’s £909 for the proper lens with an actual warranty, proper box and all instructions etc.