TrimmerTrap's BB-1 Walk Behind was the first and only discharge baffle designed to maintain compliance by operting in conjunction with the factory installed discharge shield on your mower. When using the Blade Blocker, the labor to clean up will be considerably reduced! Best of all, your customers won't complain about the grass clippings in those freshly mulched areas. The unique design incorporates a multitude of features that provide versatility and adjustability. The Blade Blocker installs on practically any commercial mower.