Special Features:

Jwhipple; grid pattern; no graduations; 21 mm outside diameter; 1-2 mm thickness; for use in the eyepiece of microscope, former item 6650-00-526-7785, to measure or count objects viewed or to limit field observed

Properties:

An item, usually made of glass, having fine wires or hairs, or etched or printed fine lines on a surface, and placed in the focal plane of an optical instrument to establish a reference point to the axis for the purpose of aiming, measuring, ranging, and the like. Excludes lens, optical instrument.