Compressive Strength : 8,500 psi - Expansion : 0.12% A fine all-purpose stone compounded to produce smooth, strong casts. ** Includes Scoop ** Hard, quick setting, accurate laboratory stone used for study models, working models and flasking procedures. Setting Time : 8-10 Min Water / Powder Ratio: 30ML to 100g Plastic Scoop Included with Plaster