HAPDEN 3 Hole Punch Tool for Grommet: Heavy duty eyelet tool kit supports 6mm 10mm 12mm grommet sizes with 200 silver grommets in each size. 3 sizes of grommet pliers kit for most DIY grommet needs! Widely Used: Easy to use whether it's grommets for tarpaulin, fabric, bag, tents, awnings, cardboard, curtains, canvas, flags, belts, shoes or banners, etc. About rust prevention for grommets: Due to the magnetic attraction function, even though the eyelets are made of chrome-plated metal with rust prevention capability, they are recommended for indoor use. Handheld Grommet Press Machine Precaution Before Use: For materials that are too thin or too thick, please use our hole puncher to make the holes before using the grommet installation kit. In addition, the correct installation of grommets and washers also affects the punching effect, you can see the instruction manual or tutorial video.