Amazing design possibilities are yours when you use this design mandrels set. The set has an assortment of seven 4 inch long (100 mm) tapered steel mandrels in 7 shapes. You can use them for making jump rings and other findings,wire work,fabricating bezels, PMC, and wax patterns among other things. Made from steel The sizes are (please note these are approximate measurements): Square (3mm to 11mm), Rectangle (2mm x 1mm to 9mm x 12mm), Triangle (3mm to 13mm), Oval (4mm x 5mm to 11mm x 14mm), Heart (4mm to 14mm) and Teardrop (2mm x 4mm to 10mm x 13mm). The set includes the following shapes: Square Drop Triangle Star Heart Oval Rectangle