This 1.5" Tri Clover Compatible Sight Glass includes silicone seals and can be easily taken apart for cleaning. One popular application for the 1.5" Tri Clover Compatible sight glass is to attach a cap to one end and then clamp it to the dump valve on a conical fermenter. The glass insert allows you to watch the flow of your beer during transfer and allows you to monitor the oxygenator flow. Sight glass also makes a great yeast collection cup. Sight glass is constructed of glass and stainless steel.