Facom 55A Series Offset Box Wrench - the 13/32" size is common for small engine repair (ie, lawnmowers). The offset and thin-wall box end improves access to recessed fasteners. 12pt (30 degree increments). OGV profile transmits torque through the fastener flats instead of the corners to reduce wear.
Current production - open stock. Facom's 55A series wrenches are available in a variety of box and module sets.