*Discontinued by Hasselblad. Please contact us to check on inventory status. 1-800-CALUMET (800-225-8638)* Unique features include the latest and brightest Acute-Matte D focusing screen, an ingenious gliding mirror system (GMS) which eliminates mirror cut-off with any focal length lens or extension tube. The 503CW was designed to be operated with the optional Winder CW, a compact and ergonomic motor drive unit. The 503CW features a built-in TTL-OTF flash metering system and the option to use the Winder CW, convenient fo studio or location work. The Gliding Mirror System (GMS) provides a full viewfinder image with virtually all focal length lenses.