Tollco Sealing kit with 3 different types of seals. The white polyisobutylene sealing tape is single-sided and perfect for sealing pipe penetrations around pipes and over joints and cracks. The black sealing tape is double-sided. It is used to seal joints between 2 materials, e.g. the cabinet bottom and the Tollco Sink liner for cabinets. The grey sealing compound is shapable and easily seals screw holes or can be wound around pipes and in cracks.