Winshield Hardware for a bass boat

I hope somebody has been down this road and can help...I am going to take my windshields off of my dual console bass boat, and I need to replace the grommets or washers that are around the mounting screws. I've looked on I-boats and West Marine's web sites, and can't find them...where do you get those things, and what are they called? Thanks!

I think they are just a recessed plastic washer. I just took mine down to the local hardware store and they had them.

I'll go down and look...thanks yote. I've not really inspected mine that closely, they look to be neoprene and maybe painted white? They look faded...thanks!