Bar's Products' Rislone Compression Repair with Ring Seal, No. 4444, is a proprietary blend of petroleum additives developed specifically for higher-mileage engines suffering from decreased or uneven compression. Compression Repair works to free sticking rings and reduce friction and wear. Polymer fills in scratches and grooves in the cylinder walls, and the polymeric film eliminates blow-by gasses. The product also contains Ring Seal, a heavy-duty cleaner that removes by-products created by combustion gasses and thermal breakdown. Compression Repair works with conventional, high-mileage and synthetic engine oils in any size diesel or gasoline engine.