The PROFORM tapered ring compressor is an affordable an easy way to install your pistons! By creating a slight squeeze on the piston ring the compressor eases the piston into the cylinder bore. Manufactured for engine blocks with studs.Proform Engine Piston Ring Compressor 67449Specifications: Feature/Benefit The PROFORM tapered ring compressor is an affordable an easy way to install your pistons! Tool Type Piston Ring Compressor Tools Category Ring Compressor Description_ABR Compressor Description_SHO Ring Compressor Description_INV Piston Ring Compressor Description_INV Tapered Description_INV 4.040 Description_DEF Engine Piston Ring Compressor Description_ASC Engine Piston Ring Compressor Description_ASC Tapered Description_ASC Fits 4.040 Inch Piston Bore Description_ASC Red Finish Description_LAB Engine Piston Ring Compressor Description_LAB Tapered Description_LAB Fits 4.040 Inch Piston Bore Description_LAB Red Finish Description_DES Engine Piston Ring Compressor Description_DES Tapered Description_DES Fits 4.040 Inch Piston Bore Description_DES Red Finish Description_EXT Engine Piston Ring Compressor Description_EXT Tapered Description_EXT Fits 4.040 Inch Piston Bore Description_EXT Made From High-Quality Aluminum Description_EXT Red Anodized Finish Description_EXT Sold Each Description_MKT The PROFORM tapered ring compressor is an affordable an easy way to install your pistons! By creating a slight squeeze on the piston ring the compressor eases the piston into the cylinder bore. Manufactured for engine blocks with studs.