Photo: Blowing quietly in the wind

An air-quality management district in Southern California is offering the Stihl BR 500 for $200 to landscapers who turn in older leaf blowers, which tend to be noisier and more polluting. The agency hopes to put 1,500 of the new blowers into the hands of landscape workers, who are the primary users of high-powered models. The BR 500 backpack leaf blower uses a four-stroke engine that is about five times cleaner than the more common, two-stroke models generally used by landscapers. The new machine also operates at a relatively quiet 65 decibels.