BJ Enterprises Jarhead Tank Gauge is a sight-glass tank gauge that indicates contents in 1/4-tank 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 2 NPT threaded tank fitting. Tank depth MUST be specified in inches when ordered, but all gauges from 18" to 60" are available at this price level.