DURABILITY: Made of heat-treated chrome vanadium steel (CR-V) with a protective black oxide finish for superior strength, anti-corrosion, and rust resistance. UNIQUE DESIGN: Beveled drive ends help guide adapter or reducer smoothly onto drive tool. Four detent grooves provide a secure connection with the drive tool. DETENT BALLS: Detent ball on each adapter end provides a secure fit into the socket, providing support when used with high-torque impact-rated drivers. Spring-loaded detent balls securely latch onto sockets, preventing them from being dropped. SIZES: This set includes a wide array of adapters and reducers. It will add great versatility by including the following conversions and sizes: (3/8 inch to 1/4 inch), (1/2 inch to 3/8 inch), (3/8 inch to 1/2 inch), (1/4 inch to 3/8 inch). PRODUCT SPECIFICATIONS: Manufacture Country: China Sizes: (3/8 inch to 1/4 inch), (1/2 inch to 3/8 inch), (3/8 inch to 1/2 inch), (1/4 inch to 3/8 inch) PACKAGE INCLUDED: Socket Converter Adapter Reducer 1 Set Note: Due to manual measurements and slight color variations, please allow 1-3 cm (0.4-1.18 inches) difference due to different display settings. Due to lighting and screen differences, the item's color may be slightly different from the pictures. Please understand.