The product features chromium-vanadium alloy steel that has been heat treated. The spherical heads allow a 25-degree entry angle around obstacles. The articulated case opens flat. The long handles provide additional reach and greater torque. The sizes are marked on the case for quick size selection. The set includes 9 multi-size handles: 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10 mm. The length of the longest handle is 260 mm.