dont know what youre talking about or asking so Ill give it a shot. the yellow bow roller is made out of a tougher rubber than the black one and wont split near as easy. Since it harder and yellow, it wont leave a black streak from loading and unloading on the trailer. If you order one it comes with the two black end caps which has grooves cut into it so that it fits snuggly up against the yellow roller. This prevents the keel from findings it way between the black and yellow roller and damaging your bow with the metal frame. other than that i dont know what is up!?Last edited by PhilAddison on February 29th, 2012, 2:10 am, edited 1 time in total.