Standard coatings for the protected mirrors is a protected aluminum, customized coatings are also available.
The Tool Cube consists of three front surface mirrors that have been accurately assembled by a proprietary process into a mutually orthogonal inside corner. The deviation from a perfect 90° angle between any two mirrors is less than 1 arc second.

The PLX Tool Cube is mounted in a housing that includes two adjustment knobs for leveling/aligning the tool cube.
It is available in two sizes, either 3 inch mirror faces or 5 inch mirror faces. Standard coating for the mirrors is a protected aluminum, customized coatings are also available.
The Tool Cube is typically used with two or more lasers or autocollimators to establish orthogonal axes.