10" UNI-SERVO BRAKE SERVICE KITS. Qty. 4, Primary & Secondary Retractor Springs; Qty. 2, Adjusting Screw Springs; Qty. 4, Shoe Hold Down Pins; Qty. 4, Shoe Hold Down Springs; Qty. 8, Shoe Hold Down Washers. For assemblies: R.H. - MPD 159-80770 & L.H. - MPD 159-80780.