Is this Washer Important?

[Z71_Denali]

I just got my PC7424XP complete with all the polish, 6" pads and 4" focus pad kit today. i took the 6" backing plate off the polisher that was on it in the box to see how the 4" backing plate fit, then noticed this on the carpet...

 

 

what does it go to, and do i need it? i noticed there was another washer on the 6"backing plate that stayed on the threads after i removed it.

 

its about the size of a dime. i'm broke after buying this kit, and some homebrewing stuff, so all i had was pennies

[Chris@Adams]

With the Adam's backing plate you won't need that washer!

[Bill-V8V]

That washer comes with the stock PC, it is used to allow enough space between some backing plates and the PC to get the wrench in there. I don't believe you need it with the Adam's backing plate. Just throw it in the box