This is a new throttle assembly. It is for 7/8" bars. Perfect for the retro bike. The housing is made of chrome plated metal. The overall length is 5 1/2" long and the throttle tube that the grip fits onto is 4 1/3" long. The part that the cable slips into is 1/4", but could be drilled to fit a larger size cable housing.  There is also a friction devise that you can adjust for a certain pressure on the throttle, or adjust it back and have none.