These 3 sided prisms are used to deflect a beam thru a 45 degree angle. Shortest side is 25mm by 40mm wide, and the longest side is 43mm long by 40mm wide. . Made of BK7 optical glass with 60/40 surface quality, dimensional tolerance of +-0.20mm, angle tolerance of +-5 arc mins, and 1/2 wave flatness. The larger reflecting surface is aluminized and protected by black paint. Unused.
