OTC's Heavy Duty Valve Spring Compressor quickly and easily compresses valve springs for removal or installation. Heavy duty steel C-frame has a 9" opening with a 5" throat. Kit includes 16 mm, 19 mm, 23 mm, 25 mm, and 30 mm valve spring retainer adapters. Durable blow-molded storage case keeps tools contained and organized so they are ready when you need them. 1 year limited warranty. 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.