Better bilge drain

Hi all. I need help sourcing something. A while back I saw an ad for a replacement drain fitting that had a threaded plug on the outside instead of the expanding rubber bung. It also has a check valve that in theory would save you if you forgot to put in the plug (or it fell out). I am replacing my transom and think this would be a better choice. Anybody heard of this and know where to get one?
thanks in advance
Jeff

 

available at most of the larger marine stores
Just google Self draining transom plug. Many inflatable use them. They are especially useful if the boat is stored say on the roof of a larger boat where it is difficult or impossible to flip them over to drain rain water out of.
Do not rely on the check valve as the only backflow preventer as even a small bit of debris will disable the ability of the check valve to stop the ingress of water.
Additionally, if you can find the type that the main screw on plug is on the inside, (these types of drains do not get rid of 100-% of the water,) then you do not have to lean over the transom to screw on the plug if you forget before
launching.