Read the Official Soap Kitchen blog:
Soap Making Magazine
70mm diameter spherical stainless bath bomb mould supplied in two halves.
Also available in 50mm and 80mm.
Important... When using these moulds to make bath bombs, slightly over-fill each half, then bring them together firmly, compressing the contents into a single shape before carefully removing one half, keeping the contents in the remaining half until sufficiently hardened to remove completely. Always wash your moulds thoroughly after use to remove all traces of fragrance and ensure maximum useful life for your mould.