Sealing Fast is a modified-bitumen-based two-component sealant. When the components are mixed, a special hardening reaction takes place that causes the sealant to harden in a short time. Sealing Fast is safe, easy to apply and can be used at outdoor temperatures between 5 and 30 °C. Unlike with hot sealants, no thermal shock occurs at lower temperatures with Sealing Fast, such as when applied to cold road surfaces.