Install Pistons 4.00 to 4.080 inch Size. Powerhouse Adjustable Tapered piston Ring Compressors for installing the piston with piston ring into block, work just like our solid models, except that they incorporate a split down the side and a large hose clamp for adjustment. Perfect for those who will be working on a variety of bore sizes or for those sizes not covered by our standard piston ring installers compressors. Each model has a range of about .090", so one of these can replace several of our regular style. Hard anodized for wear and color