65.50mm Ring Compressor. Wiseco Tapered Ring Compressor Sleeves, machined from Wiseco sleeve forgings to offer the same toughness as Wiseco?s forged pistons. Hard anodized and Teflon coated for low friction and prolonged wear resistance. Sleeves have a smooth radius that tapers down to the specific bore size. Compresses the piston rings smoothly and evenly. Greatly reduces the difficulty with installing thin high-performance oil rings. Available in bore sizes ranging from 65.5mm - 79.00mm. Part No. 00-480.6550