The GTS PS Series Peep sight is a rugged flame observation device designed for safe and reliable visual inspection of burners, furnaces, boilers, kilns and combustion chambers. It provides a clear view of the flame and combustion process, allowing operators to monitor burner performance, observe combustion conditions and identify abnormal operating conditions without interrupting the process. The Peep sight uses heat-resistant viewing glass with a reliable sealing arrangement and rugged metal body construction. Its compact design, easy installation and low-maintenance operation make it suitable for continuous industrial applications. Models are available in sizes from 3/8" to 2", with optional cooling air connection for high-temperature models.