Replacement Venus 2000 Receiver End Cap
The No Valve end cap is for the perfect seal on a very symmetrical penis with a firm erection.
No air is getting added to the space between the penis tip and the end cap. Less than 1% of these are sold or used.
The 1 valve cap is for about 94% of the users. A little air seeps in and creates a pocket of air at the tip that causes the receiver to push off a little with every stroke. This one valve can remove just enough air to help keep the air pocket from causing a pop off situation.
The 2 Valve cap is for about 5% of users. The penis may be tapered. They may use alot of lubricant or have fluids that gather in the end cap and can possibly clog 1 of the 2 valves. Using a 2 valve cap can cause too much air to be expelled leading to a lack of stroke if the valves are removing more air than what is let in creating a suction at the tip.
End caps are not expensive and it may be something you wish to experiment with.