BostikSeal N Flex 1 is a low modulus, one component, Class A polyurethanesealant. When cured it will form a tough, flexible seal capable ofcyclic expansion and compression movement of 100% (+ 50%) of theoriginal installed joint width.It has excellent resistance tonormal weathering conditions such as rain, sunlight, snow, sleet,ozone, atmospheric contamination and pollution. This abilityenables it to retain its original properties after years ofexposure, refer to the CSIRO RILEM LONG- TERM SEALANT DURABILITYSTUDY DBCE Doc. 97/196 (M)