... not cracked, high durability,light weight ,good hardness, elastic and good toughness, easy to cooperate with engineering arcmodeling, low attrition ... bear normal throw not damage.2. Gypsum will produce tiny fiber and dust, damage the respiratory system. ERC is high polymer ... , gypsum is heavier, so the logistics, installation, maintenance and so on all is more troublesome, cost is high. ERC material ...