Replacement Boston air valve for JetPilot tubes. The Boston Valve is a screw-on, two-way valve. The bottom portion is screwed into the towable, while the top is screwed open for inflation and then tightened after inflation. Air is easily released by unscrewing the base connector. It's important not to miss a thread when screwing in the Boston Valve as it may cause the tube to slowly leak air. Boston Valves can be replaced easily.