By adding a wedge, it can be used as Percision Penta Prism. It is often used in Plumb Level, Surveying, Alignment, Rangefinding and Optical Tooling.

Specifications

Material: BK7 Grade A optical glass
Dimension Tolerance: ±0.25mm
90° Deviation Tolerance:
Precision series: up to 10 arc seconds
Flatness:
Precision series: up to l/4 at 632.8 nm
Reflectivity: R > 95% per face from 630 to 680 nm
Surface Quality: 60-40 scratch and dig