EF mount.
 
The EF 100-400MM F/4.5-5.6L IS II USM is ideal for photographers who are travelling light and want to take just one telephoto lens with them. A great choice for sports and wildlife photography – the 100-400mm zoom range puts you right next to distant subjects, and lets you react quickly in a fast-changing situation. When used on cameras featuring APS-C sized sensors, the EF 100-400MM F/4.5-5.6L IS II USM offers angles of view equivalent to a 160-640mm on a full-frame camera.