Penta prism can deflect light by 90°, and it is a five-sided prism. The reflected light is not affected by slight movements of the prism, making it suitable for defining right angles in optical systems. K9 optical glass is an optical material with excellent wide-spectrum transmittance. It exhibits high transmittance and hardness in the range of 350 nm to 2000 nm, allowing it to withstand a variety of physical and chemical stimuli, while also featuring low bubble content.