Review on 225 Pcs O-Ring Assortment Set - 18 Sizes Rubber Sealing Gasket Rings Washer Seal Kit for Plumbing, Automotive, and General Repair by David Urbanski

For that price you can probably only get a dozen or so grommets from your local big hardware store... That is, if they're at least the right size for you. You can get almost any size you want here. There are also a variety of other uses for them that many people may not realize. Any flashlight that claims to be waterproof is likely missing a gasket or two in key places. If you ever want to drill a screw into something and don't want water/moisture to get in, use a washer. I wish this kit would also include larger diameter shims, but I think it might be more of a specialty item. For general purposes, you can't go wrong here.