Park Tool Hex wrenches made from industrial tool steel. hardened and tempered for shop use. Shop quality L-Shaped stubby hex keys fit into tight fixtures such as caliper mounting bolts and chainring bolts. Made from high-torque industrial steel with chamfered tips for tight tolerances. 1.5. 2. 2.5. 3. 4. 5. and 6mm hex sizes fit neatly into carrying case. HXS-3 Hex Keys are intentionally kept very short 6-20mm in depth to be the specific tool needed to reach fixtures where standard hex keys are impossible to reach.