Sarros Slate Stone is a type IV die stone formulated especially for use with cad cam systems. Sarros Slate Stone has an extended working time thereby enabling the pouring of multiple cases. With low expansion and high compression strength Sarros Slate Stone is the ideal choice for all of your cad cam restorations. Sarros Slate Stone provides excellent reproduction of detail, dimensional stability, edge strength and is resistant to abrasion and fracture. Because it is an all natural gypsum, there is no problem with stability and has a much longer shelf life compared to synthetic Diestones. Sarros Slate Stone is compatible with many types of impression materials available in the market today. Set time of 12-14 minutes with an expansion of 0.070-0.075% @ 2 hours and a compressive strength of 18'000psi when dry.