The Ko-ken RS4010M/10-L50 1/2" Square Drive Bit Socket Set is a versatile 10-piece collection designed for a wide range of fastening tasks. This set features hex bit sockets in sizes ranging from 4mm to 19mm, making it suitable for various applications. Each socket has a length of 50mm and is securely mounted on a 300mm rail, ensuring organized storage and easy access. Engineered for durability and reliable performance, this bit socket set is an invaluable addition to any professional toolkit, delivering efficiency and precision in every operation.