This grinder is not suitable for industrial and scientific work. It lacks the power required to function effectively and frequently jams, causing frustrating delays and downtime on the job..
Probably the worst tool I've ever bought. The collet was not tightened on the bits, so the item will not work. 12V means it has a 12V DC motor powered by a 12V AC supply rather than a battery. During operation, the roar of the motor can be felt in the plastic case. I have a couple of rotary tools and this one looks like a kid's toy in comparison. The item has been returned.