Roof prisms  also called right-angle roof prisms or Amici roof prism are reflective optical prisms that contain a section where two faces meet at a 90° angle. These two 90° faces resemble the roof of a building, giving this prism its name. The hypotenuse of the roof prism exploits total internal reflection (TIR) to reflect the image through the prism. Roof prisms redirect a light beam by 90° and at the same time invert the light beam. In passing through the prism, the image is both deflected right-to-left and top-to-bottom, this trait make them ideal for applications in binoculars, spotting scopes, and optical instruments.

Shanghai North Optics offers roof prisms made from BK7, UV fused silica, and other optical glass,  optional silver coating on the roof surface is also available.