Description: Corner cube retroreflector, also known as a CCR or trihedral prism manufactured from fine BK7 optical glass Typical corner cube designs reflect the incident light at 180 degrees. Some applications require the reflected ray to return at a different angle. A number of coating options are available for corner cube retroreflectors. The front face may have an antireflective (AR) coating applied, and the three reflecting faces may have a metallic or dielectric coating, or may remain uncoated Corner cubes are used in a wide variety of applications such as spectroscopy, laser resonator cavities, land surveying, ground based range-finding, satellite communications and space vehicle docking Specification: Material: N-BK7 Diameter:25.4mm / 1inch Height: 20mm / 0.79inch Dimension Tolerance: +0/-0.2mm Surface quality: 40/20 Surface Flatness: λ/4 @632.8nm 180° 180°Deviation Tolerance: 90% Bevelling: 0.25mm x 45° Coating: there reflected surfaces are coated with copper or silver,and exterior with protected black paint Package Includes:(5 Pack) 1pc Trihedral Retroreflector