This grout sample box is an alternative method that follows the guidelines to ASTM C-1019 / UBC 21-18 and will save you money, time, labor, and space. Engineered-slotted corrugation retains moisture while simulating cmu absorption rate. Each box produces 4 specimens, 3 6.25 mm x 81.5 mm x 162.5 mm. Shipped 25 boxes per carton.