Sturdy black grommets sized 8 mm (5/16 in) for ventilation, lacing and reinforcement on accessories and apparel. The set includes a matching hand tool to install clean, professional-looking rings that won’t fray fabric edges. Ideal for tote bags, banners, aprons, costumes and home décor. Works best on interfaced woven fabrics, canvas or vinyl; mark positions, punch or pre-pierce holes, then set on a hard surface using firm, even taps.