OTC's Piston Ring Compressor Plier Set features 6 different flexible metal rings to accommodate many different piston sizes. Covers 2-7/8 through 4-3/8 inch piston diameters. Ratcheting lock holds handles in position for easy piston installation. Durable blow-molded storage case keeps tools contained and organized so they are ready when you need them. Value is at the core of the OTC tool and equipment portfolio. For a simple repair or the most complex drivability concern, these award-winning tools universally solve problems faster, and at better value, than any other product line available. Whether it's a specialty tool or unique piece of service equipment, OTC provides top solutions to modern automotive service challenges while increasing technicians' productivity and shop profits.