Good uf you have to cut square holes on a routine basis for the sizes it is made for.
BUT, the listed price is £200, plus shipping. Expensive.
No dust collection, either integral or as an accessory.
A jig made with planed lumber, sized to the correct opening, with some non slip rubber on the back, and an oscillating tool, would likely be almost as quick, would provide dust collection in many cases, and all around would probably be a better option. The oscillating tool could also be used to build the jig.
Again about the price. That price only seems to make sense if an electrician is using completely unskilled, or incompetent labor, and needs a heck of a lot of holes cut. A $50 price, give or take, might sell, but £200!