Hylomar Aerograde Ultra is a highly engineered, polyester-urethane based non-setting and nonhardening gasketing compound, for use in the aeronautical industry. Hylomar Aerograde Ultra was developed in response to requests from Rolls Royce - Aerospace Division for a chlorinated solvent free version of Hylomar Aerograde. Aerograde Ultra can operate at temperatures between –50°C and up to + 250°C.