Wide view flow sights can be used in either horizontal or vertical pipe runs to observe fluid flow clarity. Large cylindrical sight allows 360° viewing and flow is readily seen from a distance, in elevated or dimly lighted conditions. In vertical pipe run, fluid flow should come in from bottom to note ball action as a flow indicator. The ball stop slightly restricts flow. Standard Features: 1/2, 3/4, 1, 1 1/4, 1 1/2, or 2 inch female connection Caution: Scratched glass significantly reduces pressure rating.