Universal Rubber Sprue Base for Casting Flasks
- A rubber sprue base with round button suitable for flask sizes 2.5″, 3″ and 3.5″
- Use when casting jewellery
- Can fit to a perforated or solid casting flask to form the base of the casting tree
- Hold the casting flask in place and forms a leak-proof seal
- Universal base can be used with the three different sized flasks