L-keys for hexagonal socket screws Hex-Plus allows socket head screws to live longer L-keys are quickly to hand thanks to their size markings Wear-resistant size marking Wear-resistant clip material for enhanced durability L-keys with thermoplastic sleeve (SPKL) out of easy-to-grip circular material. The sleeve ensures that work is pleasant and easy on the fingers even at low temperatures. All L-keys are quickly to hand thanks to their colour coding and size markings. The wear-resistant clip material ensures secure storage of the L-keys as well as simple removal. For hexagonal socket screws.