The Fein MultiMaster RS is a variable speed oscillating tool for cutting, sanding and grinding. It is produced by C. & E. Fein GmbH, along with a broad assortment of accessories.
When Fein's patent expired in October 2008, other tool makers started creating similar products, such as the Dremel Multi-Max, Bosch PS50 Multi-X, Rockwell Sonicraft, and Proxxon Delta Sander.