ATC F Wrench 50mm Heavy Duty f wrench 50mm Single Sided Speciality  (Pack of 1)

An adjustable spanner is an open-end wrench with a movable jaw, allowing it to be used with different sizes of fastener head (nut, bolt, etc.) rather than just one fastener size, as with a conventional fixed spanner.[1] Several other names are in use, including casually imprecise use of the India trademark crescent wrench.