Unused beauty in original packaging. 20mm X 20mm cube beamsplitter. Transmission and reflection is in the ratio of 50/50. Made of BK7 with surface quality 60/40. Angle tolerance is +- 3 arc min and flatness is about 1/2 wave. All sides are antireflection coated. Edmund's 20mm X 20mm sells a similar one for $125.90
