uxcell 6Pcs Stainless Steel Single Way T Shaped Aquarium Air Flow Control Valves

These have worked great for linking air tubing for several aquarium sponges along the backside of my aquarium. I ran one line of tubing along the upper back of my aquarium, inserting these T's above each aquarium sponge. This resulted in a much neater appearance and made the tubing fade to the background. I can individually control the air flow to each sponge filter. Having both plastic and metal valves, I prefer these metal ones as I feel they are more durable. If I decide to change things around, I will not have to worry about cracking plastic when changing tubing. I use these with standard sized air tubing. So far, they are great.