Opticians Universal Adjustable Trial Frame with Removable Magnifier

Patented June 25, 1896. Primarily used by watchmakers, jewelers, opticians, and the like. Distance between lenses have knob adjustments, and angles can be rotated along the gear mechanism. Lenses are adjustable and interchangeable (pictured with bue & red lenses). Square lenses are a magnifier that can be removed by unhooking from frame. American or British made.