This is a top quality ring stretcher and reducer. The highly polished enlarging mandrel has six splines and can take rings from size 1-15 (US sizes). It is calibrated and graduated in 1/2 sizes for smoothly and accurately enlarging rings. The reversible, reducing plate resizes ring shanks up to 12 mm wide by compression. The plate has 16 reduction dies. The reducing plate is used to slightly reduce the size of plain round bands, usually around 1/2 The entire tool is made out of hardened steel with a grey painted base. It can be bolted to your bench or used as a portable unit. This deluxe model measures 15.5 x 4.5 x 7.5” (39.5 x 11.5 x 19.0 cm). Not recommended for use in making coin rings.