These Wera 3950 PKL/9 Stainless Hex-Plus Keys are intended for use with stainless steel screws. They are made from a specially developed stainless steel to ensure that they have the necessary hardness and rigidity required for workshop use. Since any wear debris produced by the key is also made from stainless steel, the problem of extraneous rust or pitting corrosion on stainless steel screws is eliminated. The stainless steel is also extremely corrosion resistant, making it suitable for areas that are regularly subjected to high levels of humidity. Wera's unique Hex-Plus system uses a head geometry that guarantees longer life for both screws and tools, whilst providing increased torque. This achieved by the hex key having increased surface contact with the screw, which reduces the notching effect inside the socket. A ball-shaped head at one end provides the flexibility for "off angle" applications. The set supplied in a practical rubber clip, which provides a permanent hold on the L-keys until they are required. The following sizes are included: 1.5mm x 50mm, 2.0mm x 100mm, 2.5mm x 112mm, 3.0mm x 126mm, 4.0mm x 140mm, 5.0mm x 160mm, 6.0mm x 180mm, 8.0mm x 200mm, 10.0mm x 219mm Product Specification: Stainless Steel Construction Prevents Extraneous Rust Hex-Plus System For Longer Life Round Shafts Ergonomic Rubber Sleeves Ball Shaped Head For "Off Angle" Applications