Combinations: grommet kit set includes 100 sets of grommets eyelets (each set includes 1 eyelet and 1 washer), a hole cutter, a matched mandrel and a storage box. Eyelets Size: 1/2 Inch (12mm) internal hole diameter, 4/5 Inch (20mm) outside flange diameter, and 1/ 5 inch barrel length. Rustproof: Made of quality copper material with very great corrosion resistance and bright looks, very hard to rust. Easy to Use: Easy to set the grommets eyelets in place with the hole cutter and matched mandrel; The mandrel has a distinctive pattern on the surface, non-slip provides more secure grips. Grommet Tool Kit: Provide an economic solution for repairing canvas, tarps, tents and pool coverings, good for shoes/ shoelaces, clothing, crafts projects, etc., Manufacturer: Bestgle