7 8 Combination Wrench

combination wrench
A wrench or spanner is a tool used to provide grip and mechanical advantage in applying torque to turn objects—usually rotary fasteners, such as nuts and bolts—or keep them from turning.
(a crescent or ring on each end)

7 8
SE scale is a designation used by a growing number of modellers to describe miniature (model) trains which run on either Gauge 1 track or O gauge track. In SE scale, 7/8ths of an inch equals one foot, which is a ratio of 1:13.7.