Penta prism is a pentagonal prism, a penta prism may reflect light rays through a 90 degree angle by two reflections and inverts the image. The reflecting surfaces are aluminized.
It is a fixed steering angle device, that is: all of the transmission of light were 90 ° turn
It is a key component of range finder can also be used for SLR cameras.
| Product Number | a=b=c | Diameter | Reflection Angle | ||
| MPB-20 | 20.0 mm | 21.6 mm | 90°±3" | ||
| MPB-25 | 25.0 mm | 27.7 mm | 90°±3" | ||
| MPB-30 | 30.0 mm | 32.5 mm | 90°±3" | ||
| MPB-40 | 40.0mm | 43.3mm | 90°±3" |
