These are universal snorkel intakes for use with any pump-based ballast system. Comes as pictured above with float ball, body and brass tube installed and ready to go. 
 
When in the open air, the ball falls to the bottom of the valve, allowing air intake. When submerged, the ball float upward, sealing the intake. This was designed specifically for use with systems such as the R&R WTC, which I represent. As such, the actual seal interface is specifically designed to offer a slight leak. This is vital, as without this feature, the valve would not open if you are running your pump and the snorkel breached the surface, as the air vacuum would keep the ball sucked against the body. With a small leak, the pump can still pull a vacuum and blow ballast for full static diving, but the valve will open as soon as it breaches the surface. 
 
Do not purchase this unit and then complain that the seal leaks. It is designed this way and must operate in this manner for proper operation of the ballast system. 
 
Price includes free domestic US shipping. International destinations may require a supplemental invoice depending on country and address. 
 
Snorkel dimensions (body only):
Height: 14mm
Length: 16mm
Width: 11mm