A borosilicate sight glass fused to a metal ring. A unique combination of glass and metal places the glass in compression, creating an amazingly strong and reliable sight glass. METAGLAS® is the No. 1 selling sight glass, installed in more locations around the world. Clamp-style, bolt-on, weld-on, and threaded models available.

Metal fused sight glasses „METAGLAS^®” consist of a sight glass that is fused into a steel ring.The different expansion coefficients of glass and metal cause a compressive stress inside the glass. The mechanical prestress commands a higher security compared to thermal prestressed glasses. Because of the mechanical treatment of the steel ring, various constructive solutions can be realised.