This product is packed in a 4 liter bucket. Reaxyl ZX Flex makes all joint mortars more elastic. As a result, the joint mortars remain flexible and are more resistant to thermal settlement of the substrate. The joining of glued brick slips with. Reaxyl ZX-345 Stone strip glue directly on vapor-tight insulation boards requires a more elastic joint mortar than the traditional joint mortars. The addition of Reaxyl ZX Flex also improves the adhesion of the joint mortar on the 3 sides of the stones. To be used within the Reaxyl system warranty. Comes with a free Reaxyl measuring cup.