It’s just white hi temp silicone for spincasting from a spin casting mfr. I bought a 12” round and just cut it up. There is a place on eBay that sells blue Nicem silicone that is easily avail. Place ships out of florida. They don’t se
the company is waymil on eBay that carried the blue nicem. If u contact them they will list on eBay w free shipping I believe
you should be fine using any real hi-temp spin casting silicone. A premium jewelry silicone should work also . Castaldo gelato should work good and what ever the white castaldo silicone is should also be good. These silicones will prob give you 1,000 good casts.
Its no comparison to pop molds at all. These r professional silicone. You just put mica powder wher u want the mold to separate.
I have even done runners/gates so small that when the jig is cast there is just a tiny lead wire left to cut or separate. But I do use a home made bottom pour pot and it injects like a dream