The patented Shredz-All shred ring reduces debris to a fine mulch, saving time by emptying the bag less often and capable of cutting the number of leaf bags in half.* The shred ring is better for debris collection & gardening mulch.
http://toro.com/yardtools
Fits these Toro Electric Blower/Vacs: Models 51574, 51591, 51599, 51602, 51609, 51617, 51618, and 51619. Comes standard on the 51621.
* Debris reduction varies with material type and its condition.