Rubber Round-Button (C-Style) Sprue Base, 4″ Diameter 100 mm

Leak-proof, and will fit both regular and perforated flasks. Ideal for holding the sprue rod in the casting flask while pouring in the investment. Great for centrifugal casting and vacuum lost wax casting processes; made from tough, flexible, natural rubber materials, and holds 5/16″ – 3/8″ tree tightly into place.

Diameter measures 4″.