This tool is included in the category of hand tools (hand tools) wrenches.
The characteristics of a wrench are the shape of the opening head which resembles the letter "U".
This tool is a tool made of hardened steel and plated with chrome or nickel so that it is not easily worn out.
The function of this key is used to rotate (tighten and remove) bolts. / nuts that have a not very strong tightening moment.
This is because on one side the nut is not covered by the wrench side so that the possibility of release is greater when used for bolts that have a high moment.
Even though they don't have the ability to remove and tighten bolts or nuts with a high moment, the spanner has several advantages, including because of the flat shape of the spanner, the wrench can be used for narrow locations or limited spaces.