Stainless Steel Aquarium Oil-Film Skimmer Pipe Aquarium Plant Inflow Outflow Filter Tube Detachable Aquarium Inflow Pipe Adjustable Pipe’s Entrance Skimmer (16/22mm)

Good product.

They work great but they’re so unnecessarily long. They don’t actually fit the tank I wanted them for because they’re just wayyyyy too long for no reason!update: Came back to buy more of these, when i bought them they were only 20 pound. Now they're 52?! what a rip off!! Do not buy them unless they come down in price.

Perfect

Note that the model I got is not the one apparently offered on this page. There is no skimmer function. They are straight in and out tubes, with a couple of plastic mounting pieces to attach the pipes to the sides of your tank. The quality is excellent. There is no skimping IMO on the thickness of the tubing used. Note too the diameter of the required hoses conforms to the requirement of your external filter. You can get adaptors, but you're already spending quite a bit and they're not necessarily as cheap as you might expect for a couple of bits of plastic - I know from experience. If you do need adaptors then check third-party options as the branded ones are not the best value. The sizes of the tubes are what they are, so check all will be good, both internal and external. if you manage to get the right placement then they work well and look cool.