Rayotek’s 316 stainless steel/fused glass SAE J514 Sight Windows are rugged, thermal and corrosion resistant Sight Windows. Rayotek’s SAE Sight Glasses are the right choice for ultra high pressure vacuum in applications such as pumps, engines, furnaces, compressors, hydraulic systems and boilers. Rayotek SAE fused glass Sight Windows are so robust that even when cracked from mechanical damage they continue to seal and protect against release of pressure.