This Brass fitting is designed to attach to the shaft of the Whisper Wash Swivel and Connects the bar to the Swivel. 
 
This is designed to "break away" if anything large such as a rock, curb, or foreign object were to hit the bar, the brass fitting should be the part that breaks off the shaft making the repair of your Whisper Wash Surface Cleaner easier and less expensive. Instead of having to replace the bar or the Swivel, you can hopefully just replace the brass fitting and get back to work!