These beautiful bisque moulds have been handmade by Clae. 
Slump moulds are a good way to reproduce a specific size or shape when you are hand-building bowls or cups. 
Bisque moulds are lighter and sturdier than plaster moulds, and are much easier to clean.
 
Clae Bisque moulds come in 5 sizes.  This is the largest bisque mould (number 5) and measures approximately 23cm in diameter and 11.5cm tall.
(Note that because these moulds are made by hand there is some variation in measurements between each mould.)