BJ Enterprises Jarhead Gallon Tank Gauge is a sight-glass tank gauge that measures up to 275 gallons and indicates contents in 70-gallon increments with an orange indicator. The large, 4-window display is also highly visible and easily read from any direction. This unit is easy to install and features a nitrophyl float, aluminum linkage, stainless steel rods, and a 1-1/2 NPT threaded tank fitting.