I've been looking for years to buy the suction cups for Tetra spongs filters, and have finally found them at http://www.dalecombp.com/ They also have Dupla and Wisa products. I don't buy that stuff, but their prices on other stuff looks pretty good. Worth a look. -- Richard J. Sexton richard at aquaria_net Maitland House, Bannockburn, Ontario, Canada, K0K 1Y0 +1 (613) 473 1719