Product Description Socket Set, Drive Size 3/8 In., Metric, Socket Size Range 6mm to 26mm, Number of Pieces 21, Std. Socket Point Styles Included 12, Deep Socket Point Styles Included None, Flex Socket Point Styles Included None, Finish Chrome, Standard Tool (Accessory Needed for Tethering), Ratchets Included None, Sockets Included 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26mm, Standards ASME B107.5M, AS954E S3.8.1, Includes (2) Socket Rails 9 In., 11 In., (21) Socket Clips All Proto hand sockets incorporate the TorquePlus wrenching system. The TorquePlus design is a high performance drive configuration which allows for quick and easy socket engagement to the fastener flats, not the corners. The configuration employs a radius-corner design, shifting contact area and stresses over a large area of the socket, minimizing slippage. The internal design of the TorquePlus minimizes fastener rounding, helps to extend fastener life, and allows the user to more easily turn worn, rounded, or rusted fasteners. From the Manufacturer All Proto hand sockets incorporate the TorquePlus wrenching system. The TorquePlus design is a high performance drive configuration which allows for quick and easy socket engagement to the fastener flats, not the corners. The configuration employs a radius-corner design, shifting contact area and stresses over a large area of the socket, minimizing slippage. The internal design of the TorquePlus minimizes fastener rounding, helps to extend fastener life, and allows the user to more easily turn worn, rounded, or rusted fasteners.