I designed these tools after participating in a felt hat course with Jean Hicks during my residency at the Appalachian Center for Crafts in Smithville, TN in 2004. Jean was using the ribbed screw thread of a wooden plunger to full a hat while on the hat block and I thought a variant of the tool would be ideal for fulling the concave areas of hollow forms developed with extreme differential shrinkage. These tools are made by a production wood turner specifically for STRONGFELT, inc on a lathe and branded by Lisa Klakulak before sending them out!