Snap Together Grommets are washable, polypropylene grommets that are perfect for light-duty utility tasks like weather cloths, tarps, sun awnings and shower curtains. These grommets are also UV resistant and will not rust or corrode. Install a Snap Together Grommet in up to 4 layers of Sunbrella (or 0.05-inch webbing) with a #5 hole cutter and hammer. Place a piece of wood on top of the grommet and tap to set through thicker fabrics.