Still the finest quality head-mounted magnifier, the Optivisor headband magnifier from Donegan Optical features a dial adjustment head band visor to fit any head size. Well made magnifier made of light, durable material. Optivisors easily fit over eyeglasses and are easier to use than loupes. Just flip the visor down when you need it and up when you don't. Adjustable pivot assembly on visor can be set to desired tension, so it will stay in place when tilted. Optivisor glass lenses are ground and polished optical magnifying glass, prismatic type.