The Grainger Approved Therma Level Gauge HDPE is a high-density polyethylene gauge for water heaters and boilers. It features a clear, shatter-resistant tube with easy-to-read markings and a 3/4 in. NPT lower connection. Made of durable HDPE, it withstands temperatures up to 200°F and pressures up to 100 psi. Compatible with water, glycol solutions, light oils, and chemicals, it measures 18 in. long with a temperature range of -20°F to 200°F. ANSI rated and UL recognized, it offers an economical way to monitor water levels.