BEFORE YOU ORDER
It needs a standard duplex outlet.
The anchoring screw is what makes this different from a splitter, and it needs an ordinary two-socket duplex outlet with more than an inch between the sockets. It will not secure to a GFCI outlet, and it is not designed for outlets with more than two sets of parallel sockets. Worth thirty seconds with a tape measure before it ships.
Nine places to plug in, one place on the wall.