The ATS-W2H-125A-4P-WST5 is a 4 Pole 125A Automatic Transfer Switch with Solenoid open transition. The benefits over a motorised transfer switch is that the switching happens much quicker for use in critical applications such as hospitals and airports where power outages, even if only for a few seconds, can have serious repercussion.
This ATS has a seperate controller which is door mounted.