This special version of the Makin's Professional Ultimate Clay Extruder is constructed from stainless steel and especially designed with metal clay artists in mind but can be used with all types of clay including polymer clay and any type of fired clay body. An extra O-ring and 10 stainless steel discs are included with this set that are specifically sized to be appropriate for metal clay, Although all Makin's Extruder Disc Sets function with this extruder, the Ultimate Clay Extruder Disc Set E is also designed with metal clay artists in mind to provide desirable shapes in an appropriate size for the material.