Rectangular prisms(right angle prism) are used to deflect a beam of light through 90 or 180 degrees. This can be used as component to create various optical devices. BK-7 can be used for a range between the visible and infrared light. fused-silica an be used for a range between ultraviolet and infrared light. VY Optics Photoelectric Technology Co.,Ltd. offers a wide range of different materials and different degree of precision prisms.