| Material | BK7, UVFS |
| Dimensional tolerances | +0/-0,2 mm |
| Clear aperture | >80 % |
| 90˚ angle tolerance |
±2 arcmin (General type) ±5 arcsec (Precision type) |
| Pyramidal tolerance |
±1 arcmin (General type) ±30 arcsec (Precision type) |
| Surface quality | 40-20 S-D |
| Surface flatness | <λ/4 @ 632.8 nm |
| Protective chamfers | <0,25 mm x 45° |
The right angle prisms are often preferable to an inclined mirror in applications involving severe acoustic or inertial loads, because they are easier to mount, and deform much less than mirror in response to external mechanical stress. As long as acceptance angle limitations for TIR from the roof faces are not exceeded, the right angle prisms can serve as a retro reflector, turning beams back to the original direction.