Stihl MS 661 C-M ChainsawWhen professionals need to fell large trees, in large quantities, they reach for the saw they know has the power to get the job done the MS 661 C M. Featuring an impressive power to weight ratio and STIHL M Tronic engine management technology, the MS 661 C M chainsaw also delivers less vibration and 20% greater fuel efficiency than the MS 660. Other features include a long life filter system using HD 2 filter elements to provide longer run times