The wera 950spkl 4mm multicoloured ball end hexagon allen key is one of the most commonly specified sizes across professional trades, making it an essential addition to any toolbox. At 4 x 137mm, it delivers excellent leverage for driving hex socket screws in automotive, mechanical engineering, and general workshop applications. The hex-plus profile provides a larger contact surface within the screw head than a conventional hex key, substantially reducing the notch effect and protecting fasteners from rounding even under repeated high-torque use. This makes the 4mm an ideal daily-use key for professionals working with medium-sized fixings. The colour-coded hose sleeve ensures rapid, error-free size selection and maintains a comfortable, secure grip across a range of working temperatures. The ball end on the long arm allows confident angled access in restricted spaces, while the blacklaser surface treatment offers reliable corrosion resistance. Laser-engraved size markings remain clearly legible for the lifetime of the tool. Features and benefits: hex-plus profile protects screw heads and extends fastener life colour-coded sleeve for instant identification and comfortable grip ball end for effective angled access in confined installations blacklaser finish for excellent corrosion protection and durability permanent laser-engraved size marking resistant to abrasion contents: 950 spkl l-key multicolour, metric, 4 x 137 mm specifications: hex size: 4mm overall length: 137mm