STI SpecSeal® Ready® Firestop sleeve kit is designed for new cabling penetrations where the sleeves are required. This sleeve has preformed steel construction with rolled-edges, steel escutcheon plates with intumescent gaskets and a dosage of our SpecSeal® SSP firestop putty. Rolled-edges eliminate the need for bushings and the escutcheon plates and gaskets take the place of steel strut and strap supports. This 4-Inch firestop sleeve is made for the assemblies up to 10-Inch thick. Firestop sleeve kit is UL listed and Code compliant.