Direct from Oregon Outdoor Equip (previously Silver Streak). No this is not a sales pitch. I sent for the info since to find out the 411 on the blades. Here's what they say: Normal Conditions-Gator Mulcher... Mulching Wet Grass or Bagging-Gator Mulcher Hi-Lift...40% higher lift than regular gator, better airflow, less clumping Abrasive Cutting, Wet Grass, Bagging-Gator Mulcher Magnum... Same Tooth Design as Gator Mulcher, with 40% more lift, but 25% thicker....ideal for the commercial cutter. They also pitch the R50 process-innovative mfg process for increased hardness of commercial blades up to 20%.