Wilwood Caliper-Forged Superlite 4R-R/H 1.88/1.62in Pistons 1.25in DiscThe Superlite 4R caliper series is the benchmark in asphalt short track, late model, modified and open wheel competition. It also enjoys prominence in a variety of road race, rally and sport driving applications. The new FSL4R model series is the latest innovation to this Superlite family of calipers. It has been redesigned with internal fluid ports that eliminate the external fluid cross over tubes. The transfer tube has been replaced with two