Canon EF series L USM Standard lens with an aperture of f/4 is compatible with Canon Digital SLR cameras. This Canon lens is capable of being used with Auto & Manual focus. It contains 12 elements in 9 groups and features a focal length of 40 mm. The lens is compatible with 77 mm filters. It has 8.4 cm diameter, 9.7 cm length and weighs 500 g.