this handy device makes stability tests a snap. it consists of a plastic blue body encasing clear acrylic lens with easy increments 0-90 degrees in four quadrants.
as a general purpose dual-voltage isolation transformer for step-up (120 to 240 vac), step-down (240 to 120 vac), or straight 1:1 isolation (120 to 120 vac or 240 to 240 vac).