Wide view flow sights with a restrictor orifice and cylindrical sight provide maximum 360° visual observation of fluid flow, color and clarity. Mount on the downstream side of vertical lines on cooling or lubricating systems. Standard Features: 1/4, 1/8, 3/8, 1/2, 3/4 or 1 inch PTF female connection Temperature & Pressure Ratings: Maximum working temperature up to 140°F (60°C) Maximum working pressure of orifice up to 125 PSI (862 kPa)