That is what I thought you where talking about. I used them on my 165 gal and they are a pain in the arse when the wife moves the keys and cant find them, happened twice in the last month.
I was looking for these on ebay but couldn't find any, what are they actually called so I can search again.
tank will be filled in due time, I have a day job to deal with which tends to slow down my progress. By Jan 1 it will be full, running and finished ( i hope )