Maxopto Optics unmounted penta prisms provide 90° beam and image deviation without inverting or reversing the image. Penta prisms reflecting surfaces are aluminized with inconel and black paint overcoat, while input and output faces are uncoated (refer to the drawing). An important feature is that these prisms do not have to be precisely aligned to operate properly. For this reason these five-sided reflecting design prisms are essential for applications, where precise 90° deviation is required. To optimize particular application optical transsmision antireflective coatings have to be applied.