"ORIGINAL" PWC Doctor Versiplug. Simple installation drain valve, for threaded type drains. One way drain valve allows water to flow out keeping your bilge empty while you ride. Valve closes keeping water out when you stop. Made from 6061 Aluminum and anodized for corrosion resistance. Direct thread replacement for Pre-2003 Yamaha 2-stroke machines, 4-stroke Super Jet, with threaded type original drain. Much more reliable / durable than the old duck bill type systems.