3" Tri-Clover Sight Glass (Beaded) Heat-resistant PPSU MaterialUse in conjunction with a 3" silicone beaded seal and 3" Tri-Clover Clamp (3P)What is PPSU?PPSU is an excellent choice for components that are exposed to high temperatures (up to 200°C) and corrosive media due to its exceptional chemical resistance. As well as being extremely impact resistant.We have decided to use this type of plastic because it also has superior thermal and mechanical properties with the added benefit of being transparent. This will allow us to injection mold intricate parts that would have been near impossible to do in stainless steel or lab-grade glass. Because this is a very unique type of plastic, it comes at a much higher cost per kg than other industrial plastics. So much so that it costs more than stainless steel.