The Donegan AL-13 replacement lens plate has a 1.75X magnifying lens plate for hands-free viewing using an OptiVisor or AccurSite binocular magnifying visor (sold separately). The optical-grade acrylic prismatic lenses provide improved eye focus and reduced eye strain, and have a 14" focal length.
Donegan Optical manufactures precision visual devices such as magnifiers and optical loupes. The company, founded in 1952, is headquartered in Lenexa, KS.