drain cleaning bladders - a quality one - where?

[vsheetz]

Where can I obtain one of the drain cleaning bladders - a quality one. I have the rubber ones from Home Depot and Lowes - too easily damaged. I saw a guy with one that had a canvas covering - something like that is what I am seeking.

I use to assist in priming the pump of my pool system after anything on the suction side of the system has been opened.

Thx!
Vince

[toolaholic]

Plumbing supply house, about $50 for 4" one

[Twicepipes]

like this?
http://www.gorlitz.com/index.php?act=viewDoc&docId=40

http://www.gorlitz.com/skins/Gorlitz/styleImages/products/t-20.gif