The MillionAir AC/DC Auto Switch Battery Air Pump arrived today from Premium Aquatics.
The pump will work in battery only mode if you do not plug it into the wall. It does not operate if you plug it into the wall and there is power. So it is the kind of thing most of us want. It came with an airstone - but you will need to get two D cell batteries.
This was my first experience with Premium Aquatics. I ordered a bunch of odd ball stuff - because they had it listed and they were items I had intended to have around. I ordered Monday and it arrived Wednesday.