There are two specification ranges for double-ended wrench, the smaller end is suitable for nuts and bolts of 8mm to 13mm, and the larger end is suitable for nuts and bolts of 14-22mm. 

MULTIFUNCTION -This universal torx wrench with compact design and lightweight allows you to carry it with you instead of carrying a set of different size torx wrenches for the same job this one spanner can do.

Overall heat treatment, hardness up to HRC60, high quality chrome vanadium steel forging, the 8-22mm universal wrench is made of chrome vanadium steel with high hardness and super durability.  CHROME-PLATED & POLISHED -The surface of the universal wrench tool is treated with overall heat treatment and polished plating,