Following on from the success of our World Radical 2 Range. AP Racing has brought the same design philosophy in a monobloc (One piece) form for the first time in our history to the road performance market, and they are called Mono R. This latest 6 & 4 piston, one piece forged caliper incorporate our patented technology allowing the road user to experience the superior Race caliper performance that monobloc calipers offer. Offering improved rigidity and better cooling characteristics than World Radi-CAL 1 / 2 caliper designs, the Mono R represents a major innovation in our performance brake caliper options. Mono R calipers are suitable for heavier (3500kg) applications compared to World Radi-CAL 1 & 2, such as 4x4, SUV and Pickup truck vehicles. In addition the calipers incorporate all the features demanded by the road market including, dirt seals, an attractive painted finish and noise abatement solutions. 6 Piston Families:- CP9570 / CP9571 / CP9572. 4 Piston Families:- CP9580 / CP9581 / CP9582.