Sight Flow Indicators are manufactured of quality materials and safety tested to assure long, dependable service at economical prices. Available in window viewing style inthe 100 and 300 Series and tube viewing style in the 400 and 700 Series with connection choices of female NPT, BSPP, or BSPT threaded and flanged. Series 700 has impeller andinternal wipers for cleaning sight tube, which is perfect for fluids with suspended solids. Just rotate the glass tube and restore full 360° visibility without disrupting the flow.