Dwyer Visi-Float Series VFB Flowmeter, 4" Scale Length, Range 0.5-5 GPM Water, with Stainless Steel Valve, 1/4" NPT Process Connection Process Connection 3/8" NPT Process Connection All VisiFloat flowmeters have metal mounting inserts on rear for panel mounting. They can also be supported directly by system piping. The machined acrylic bodies of the Visi-Float flowmeters are practically unbreakable. The front scale location and white background provides excellent visibility. The direct reading scales are hot stamped into the plastic and will not wear off.