The Britool Expert 3/8" Female/Male Drive Couplers easily convert your 3/8" drive ratchet to a 1/4" 1/2" drive. Made with a durable Chrome Vanadium the couples easily lock in place for reliable performance with manual drive ratchets. Features and Benefits Durable Chrome Vanadium construction Convert a 3/8" manual drive ratchet to either 1/4" or 1/2" Female/Male coupling Comes with Britool Expert Lifetime Warranty for added peace of mind Conforms to to ISO 3315 - DIN 3122 - ISO 1174-1 standards Typical Applications Domestic Mechanical Industrial On site Workshop Warning For use with manual tools only - Not suitable for power tools