SUPERIOR CR-MO STEEL Constructed with heat-treated forged chrome molybdenum steel material, BOEN impact adapter set features high hardness and durability, and can withstand the test of different jobs. DURABLE & RECOGNIZABLE MARKING Different from the traditional black oxide coating adopted by others, our socket adapter set is made of black manganese phosphate coating, which has excellent corrosion resistance and rust resistance, so that you can use and keep it for a long time. Laser markings and stamped markings make all model numbers easy to keep, read and quick identification. SAFE & FIRM A spring-loaded ball brake can lock your socket in place and fix the through hole to prevent it from falling, providing excellent stability and execution. The through hole on the drive end securely locks the adapter to the drive tang. PERFECT COMPLETE SET Package includes: reducer: 1"F to 3/4"M, 3/4"F to 1/2"M, 1/2"F to 3/8"M, 3/8"F to 1/4" M