For product - there are mini circular saws for wood. More is not to be the more you do not buy here also!
Reviews that no metal are cut, in my view in itself absurd - there are blades. The blades and the barrel axis are made properly for the size and intended for smaller incisions in a softer wood, so for example, a groove for a deadbolt auszusägen. The whole is not intended for it so to make kitchen sinks excerpts from countertops. For the operation you should use a Dremel with a correspondingly high number of revolutions. In addition, attention must be paid to a tight fit of the saw - and a stable goggles understood.