Dwyer Instruments window sight flow indicators are inline piping units designed for providing a remote visual indication of the flow rate and direction. The brand's 350 Series sight flow indicators feature a brass / 316 stainless-steel body for strength and durability and a dual-window with tempered glass for preventing scratches and impact damages from flow pressure. The 100 Series models have a single window with a rotating impeller for accelerating the fluid and easy viewing from any angle; ideal for hydraulic tanks, pressure vessels and oil reservoirs. Choose from a wide range of these sight flow indicators available in 1/4, 3/8, 1/2, 3/4, 1, 1-1/4, 1-1/2 and 2 inch body size variants on Raptor Supplies, an authorised Dwyer Instruments distributor.