PTFE moulds for the manufacture of resin samples such as Technovit, JB-4 or most other similar resins.
These moulds are designed to split in the middle, this allows the user to pull them apart after the resin has cured. Often the resin fills in all the gaps on the non splittable moulds and causes them to become stuck, the splittable mould can simply be pulled apart.
We offer some fixed sizes, but moulds can be made to any specification. The base of the mould is 25.5mm to fit in a standard Optical HREM block but can be changed to user specifications. 
Each mould will have a small chamfer on the mould to aid with getting the block out, the dimensions supplied purely relate to the minimum surface size.