This is the Large Diff Case O-Ring Seal for use on the Ofna 1/8 Nitro Dirt Oval Kit (OFNC3415). FEATURES: Black colored rubber O-rings Should be used if differential is rebuilt INCLUDES: 3 large O-rings REQUIRES: Installation in differential following instructions in manual SPECS: Diameter: 27mm (1.06") cnh 11/6/08 ir/jxs