From the manufacturer's website: "Castlemolds(R) are made of the highest quality Silicone RTV Rubber available and are guaranteed to last for years and hundreds of casts. The liquid rubber for the molds costs about $200 per gallon, which is reflected in the price of the molds. I've used cheaper silicone rubber that you can buy in the hobby shops for a lot less, but after about 3 months the molds start to crack and fall apart. Once I found this quality rubber, I never went back. I still use molds from 5 years ago made of the quality stuff, and they're doing great!"
Used for floor tiles, steps and floor mosaic designs. Regular chipped stone texture. Detailed instructions for use are available frrom the manufacturer lilnk below.