SpecSeal LCC Firestop Collars are factory-manufactured firestop devices sized to plastic pipes of up to 4 in. Trade Size. LCC Collars consist of a restraining collar with a factory applied intumescent ensuring the correct amount of material is applied every time. Simplify the process of firestopping combustible piping by taking the guess work out of estimation with SpecSeal LCC Firestop Collars.