ECHO 215 MPH 510 CFM 58.2cc Gas 2-Stroke Cycle Backpack Leaf Blower with Tube Throttle. ECHO 215 MPH 510 CFM 58.2cc Gas 2-Stroke Cycle Backpack Leaf Blower with Tube Throttle The ECHO PB-580T Gas Backpack Blower features a 58.2cc professional-grade, 2-stroke engine with a tube-mounted throttle. It delivers 510 CFM and 215 MPH blowing performance for a powerful impact. A unique vented backpad circulates air around the user for increased comfort in hot weather. Its compact yet durable design offers easy transport around your yard area.