The Prym Vario Creative Tubular Rivets Tool Set is designed to be compatible with the Vario Creative Tool. When used together, these tools work to attach hollow rivets to leather, jeans, and other thick materials. The set includes two tools in a 7.5 mm size, and two tools in a 9 mm size. To use, simply insert the tools into the Vario Creative Tool, punch through the fabric or leather, then finish with separately available rivets of corresponding size. - Prym Vario Creative Tubular Rivet Tools - Set of 4.