12-526-0 SPI Optical Comparator 12"SPI 12" Optical Comparator This Horizontal Comparator, or Profile Projector, is used with heavy parts or with shapes that require being in a fixed position. A light is projected horizontally onto the workpiece, and the profile shadow of the part is then projected onto the screen. Complete package includes the following 10X, 20X, & 40X Lenses 2 Dial Indicators 0 1" Range, . 001" Grads, Includes Cert of Calibration, # 22 300 8 0 2" Range, . 001" Grads,