Or you could build your own. I made this one and used it to connect a refugium to my sump. Worked very well. It has an airline hose at the top of the siphon connected to the input side of the return pump in the sump. That keeps micro bubbles from building up and breaking the siphon. It also provides for self priming and self starting if you have a power outage. I did a lot of testing with it too, and could not create a situation where it could fail or you could have a flood.
More pics and reading on this type of design.
http://s868.beta.photobucket.com/use...embly.jpg.html