Garreco 1483025 X-ROC EXPANSION STONE WHITE 25 LBS (9X-4090)Product Overview X Roc was developed for pouring the duplicate model in processing thermoplastic appliances such as: Flexite, Valplast, Flex Star V, TCS, FRS, DuraFlex, DurAcetal. This stone compensates for the shrinkage of these materials, thereby eliminating tight fits on removable prosthetics processed with conventional stones. Features Indication for use: Specialty duplication material. Eliminates tight fits Moderate PSI Easy to work with