Roklin Systems Inc. FlexSet Rapid Concrete Repair 5 Gallon Kit FlexSet is a cold-applied, liquid and aggregate slurry that hardens in minutes to provide a long-lasting repair, without the need for removal of damaged concrete or dig-outs of any kind. FlexSet utilizes our patented, coated aggregate, which contributes to flowability and ease of installation on potholes, joints and cracks. FlexSet concrete patch repair can be finished precisely to grade, resulting in a smoother ride over the repaired areas like driveways, runways and sidewalks. FlexSet is easily feathered into the surrounding concrete to form a repair that blends in visually with the existing pavement. In temperatures below 58, add 1-ounce bottle of catalyst to your order. This will cause FlexSet to set up faster in cold weather. Catalyst is not included.