30掳 - 60掳 - 90掳 Littrow Dispersion Prisms are suitable for many applications. Uncoated littrow dipersion prisms are used to disperse light into its component spectrum. Coated littrow dipersion prisms are used to deviate the line of sight by 60掳. Littrow prisms feature 30掳, 60掳, and 90掳 angles, are commonly used as dispersion or beam deviation prisms depending on whether the B-C surface is with coating or without coating. Material: Optical Glass, Fused Silica Size Range: 4-300mm Dimension Tolerance: +/-0.02mm Surface Quality: 20/10 Angle Tolerance: 2 arcsec Irregularity: 1/4 Lambda Coating: AR, HR, PRCustom Optical Prisms website:http://www.visopto.net/optical-prisms/