The MADRF14C/N Marumi Ring Flash consists of a main control unit and a seperate ring light which connects to the lens filter thread. This unit is ideal for Macro/Close-up photography due to the flash light being positioned directly between the camera lens and subject allowing for even/shadowless illumination. The flash has a 14m (100ISO) guide number and features auto TTL exposure. The lens mount is 52mm, step-up rings are also supplied for 55mm, 58mm, 62mm and 67mm fittings. There are 2 models which are compatible for either Canon ETTL/ETTL11 dedication or Nikon iTTL.