SCM21

I used them on a smooth plastic and they would lose suction. Works on glass. Maybe because they are on the smaller side. Wish they came with a few extra zip ties

Best of the best

Holds plants along the glass quite well

These are great for holding plants in place in the tank by securing the plant to the glass wall while the roots grow into the gravel.

The media could not be loaded.  Most reliable suction cups w/zip tie I've ever used in my fish tank. Most impressed by how versatile these are by using the zip ties. Unlimited uses. I secured all of my air tube lines just below the gravel line along the back glass inside my aquarium and after at least 10 gravel vacuumings the tubes are just where I placed them! Makes life so much easier. I also used them to hold the wires to my lights, thermometer and landscaping. Strong, lasting suction and they stay put. Highly recommend.

Small and Strong!!! Finally an aquarium suction cup that works to hold hoses (large and small) in place! Thank you!

I use these to keep pothos cuttings secured at the top of my aquarium. They work great!

Strong hold! Love them