Posted by Pumping Now! on October 24, 1998 at 09:04:43:
Attached is a diagram of my suntea jar, I'm using now. It's pretty comfortable, makes a good seal, is cheap and easy to make.
A motorcycle shop gave me a used innertube. Clamps are about a dollar.
Smaller innertubes prevent the pubis from swelling as much, but pulling pumped cock & balls out is harder. Multiple layers of innertube work well, too.