Our CWB unit is required for all commercial series walk-behind mowers. Many models will have pre-existing holes in the side of the frame to install the roller. If no holes are available, two 3/8" holes will need to be drilled. Please see the following photo for more detail.
CWB Photo
For additional information regarding this product:
Schematic Drawing
Mounting Instruction Brochure
Determining Roller Width 
