Mercury - Bulk Water-Pressure Tubing Speedometer & System Hose 32-859785100. OverviewThis 100-foot roll of gray water-pressure tubing gives you plenty of hose for long rigging runs or full system replacements. It's the same style of line Mercury uses for water-pressure gauges and speedometer pickups, flexible enough to route cleanly without kinking. Out on the water, fresh tubing helps the gauge read steady instead of fading in and out like old, brittle hose. It's a simple upgrade that keeps thi