Specification of our dove prism as follow: *Material: BK7/Quartz/other optical glass *Angle tolerance: +/-3 min *Dimension tolerance: +/-0.15mm *Flatness:lambda/8 *Surface Quality: 20-10 scratch-dig *Clear Aperture: 90% Dove Prism is ideal for image rotation. Dove prisms create an image inversion in a beam input parallel to the base.VY Optics Photoelectric Technology Co.,Ltd. can supply each kind size and each kind dimension Dove prism. The coating or painting may be available by custom orders.