The Canon EF-M lens mount, introduced in 2012, is a derivative of the Canon EF lens mount designed for use with the Canon EOS M mirrorless interchangeable-lens camera. It has an 18 mm flange focal distance (compared to 44 mm for EF and EF-S) and a 47 mm throat diameter (compared to 54 mm for EF and EF-S). As it is designed for use with an APS-C-sized image sensor, it features the same crop factor (of roughly 1.6) as the existing EF-S lens mount. It allows the use of Canon EF and EF-S lenses with a Canon-made adapter, but it is not backwards-compatible with Canon's existing DSLR cameras.