Internal TTL circuitry and hot shoe for use with certain Ikelite housings for Canon DSLR cameras, see Housing Compatibility below. Easy installation into the housing with a secure fit underneath the camera mounting tray.
Housing Compatibility
DL200 Housing for Canon 5D Mark III, IV, 5DS(R) # 71702
DL50 Housing for Canon 5D Mark III, IV, 5DS(R) # 73702
FL200 Housing for Canon 5D Mark III, IV, 5DS(R) # 6871.09
Not compatible with any other models except as listed above