This is a great buy. They give you a lot of really good suction cups that actually hold the line well. The line itself is flexible which is very helpful and also it does not come loose. It easily can fit over air stones and does not come off without cutting it off. Low hassle to use. It also works with glass CO2 diffuser very well. Does attach to clear plastic check valves easily. I like that it is black and can be hidden easily in the tank. Also, you cannot see the algae on it and it always looks clean. Doesn't kink or come off like the clear hard plastic lines do. This feels more like rubber than plastic. Should have bought this first. Threw my old lines away. Highly recommended.