Hasselblad 553ELX, a motorized version of the 503CX with addition of: Acute Matte focusing screen Universal 1/4 inch tripod socket Battery compartment redesigned to fit 5 standard AA batteries, and battery level check feature. TTL/OTF dedicated flash metering system; SCA 300 and SCA 500. Working range of the sensor is ISO 16-1000. Larger release button #46345 is supplied as standard, but the smaller release button #46116 can be used. Use release cords FK30 and FK600 in front socket. Use release cord SK150 and connecting cord LK500 in side socket. FEATURES INCLUDE: Built-in motor advances the film (up to 1.2 fps) and recocks the shutter after each exposure. Operating Selector dial allows user to choose various pre-release options for mirror movement and shutter operation. No shutter built in; uses C- and CF- lenses with built-in leaf shutters providing flash synchronization at all speeds.