Penta Prisms are designed to turn an image or light beam precisely 90° without inverting or reversing it. A benefit to Penta Prisms is the 90° turn provided by this optic does not change even when the prism is slightly rotated or out of alignment. Therefore Penta Prisms are ideal for high precision applications where exact prism alignment is challenging. To enhance overall performance, all our Penta Prisms come standard with AR coating on the entry and exit faces.