ECHO 214 MPH 535 CFM 63.3 cc Gas 2-Stroke Cycle Backpack Leaf Blower with Tube ThrottleThe ECHO PB 760LNT gas leaf blower is the most powerful, low noise blower available. The yard blowers professional grade 63. 3 cc engine produces 535 CFM at 214 MPH for quick and easy clean up of the largest jobs. The gas blower unit comes with a 5 year consumer 2 year commercial warranty. Use a 50: 1 ratio of fuel to oil mix for 2 stroke cycle engines, recommend using only fresh gas with a minimum octane rating of 89 or higher (mid grade to premium)