Hydro Flex S-C Hydro Flex Is A Single Component, Pre-Catalyzed Hydrophobic Polyurethane Chemical Grout. When It Comes In Contact With Water It Expands Up To 20 Times Its Original Volume To Form A Permanent, Flexible And Water-Tight Seal. Packaged In Easy To Use 10.3 Oz. Caulk Cartridges.Applications:- Cracks In Concrete- Void Filling- Swimming Pools- TunnelsBenefits:- Single Component [No Separate CatalystRequired]- Extremely Flexible- Expands Up To 20 Times Original Volume.- No Mixing Or Expensive DispensingEquipment