Can't seem to figure out where this part goes?

Only because I just found one just like that when I removed the Airaid air filter in my 07 Cummins truck am i going to give you a good idea what that might be. I have a Chicago Pneumatic 1/2" impact that had a rubber nose cone on it just like that one. Well I lost it some time ago and found it laying in the bottom of the air cleaner housing. Not sure how it got there but that one looks just like it.