Milwaukee fans who have invested heavily in their M18 platform. This is my first tool on their M12 platform and it didn't have me disappointed.I bought the tool only version of the rotary tool and also received a set of 2 Revain M12 batteries.Honestly I paid just a little more for the tool and 2 batteries than I would pay for a tool - only at my local dealer.As I have a lot of M18 tools I have M18 chargers that will charge both M18 and M12 batteries.If this is your first Milwaukee tool you will need an M12 battery AND for this tool a charger. clearly stated in the product description as far as I remember. However, I also bought a set of Dremel cutting, grinding and polishing attachments to use with the Milwaukee as well. Installing and removing Earning bits is very easy. Simply press the locking button and use a small wrench to loosen or tighten the chuck to lock or remove the disc holder. Replacing drives is just as easy, as you simply unscrew the pan head screw that secures the drive to the bracket and swap it out. The tool is powerful and with adjustable speed. However, the best part is that it has an auto shut off feature if the motor gets stuck or gets hot. It will start working again in a few seconds, but this is just one way to protect the motor from longevity. Also, you don't want to twist your stuff a lot. Simply apply light to medium constant pressure and let the tool do its job. Great purchase and I would highly recommend it and others in Miulwaukee.