I've gone through 3 of those. They work well but seem to fail over time. 2 of them also took a saltwater bath. Just be diligent in moving them when doing any type of work in the display or figure out a way to lock them in. I'm using velcro now. I switched to the aquachef and been using it now for 2 weeks, it seems to do the job at a cheaper price. It is a bit bulkier though. It uses the same timing scheme as the eheim. Don't now how it will work long term. Here it is: