In win 503 red amp black the new 503 offers a unique exterior design featuring a sliding tempered glass front cover which offers a clean modern look to your pc the creative design of the tempered glass front cover keeps the optical drives hidden but also slides down to allow access internally 503 accommodates high end graphic cards up to 408mm with 7 expansion slots for high performance crossfire or sli features new modern design sliding tempered glass front io port usb 30 x 1 us