A sanitary stainless steel sight glass is a flow indicator that allows you to see fluid flow in any direction inside a pipeline or vessel without physically accessing it. They are often used in the food, pharmaceutical, and chemical industries and are ideal for high purity applications. Sanitary sight glasses are designed to be hygienic, with no crevices or gaps that could trap harmful bacteria. They are made of stainless steel to prevent corrosion and rusting, which can occur when the glass comes into contact with air and moisture.