Constructed from chrome vanadium steel, these wrenches are ISO 1711 certified which specifies minimum values for Rockwell hardness and torsional strength for hand-operated wrenches and sockets, ISO 7738 certified which specifies the overall length and the maximum head thickness of combination wrenches, SAE AS954-E certified, a certification covering strength, design clearances, and torque capacity. This all-encompassing collection of combination wrenches spans sizes from 7 to 19mm, ensuring you have the best combination of accessibility and leverage whenever you need it. Includes sizes: 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19mm.