Here we are selling a late 50's GE PR-1 Exposure Meter. It's in great shape, although it's leather case's stitching is apart a bit in back. It works well. This meter’s usage is actually quite clever: Set the film speed. Press the little tab on the black inner dial and twist until the film speed clicks into the little window above the GE logo. Twist the outer dial – counterclockwise in low light, clockwise otherwise – until you see three little pointers (“tines”) pop up. Aim the meter at the subject and press and hold the button on the left side. Let go when the needle stops moving. The needle stays in place. Twist the outer dial until the center tine lines up with the needle. Look at the f stop numbers on the outer dial and the shutter speed values on the inner dial. Set your camera to any matching combination of f stop and shutter speed and you’ll get a properly exposed photograph.