It was a oscillating tool. There are many manufactures on the market now, from no name brands to a high end Fein. The main difference you will find is the degree of oscillation and like most higher end tools the smoothness in operation. You will also see they can do much more than cut wood. I find the oscillating tool to have a useful spot in my tool box. Good luck on your search and please post what tool you choose.
Yeah friend I am too agree with the oscillating tool to cut the baseboard just because of more options of cutting things other than the wood... So, I will suggest you for it.