Marine Firestop Putty (MPU) is designed to seal small to medium size openings in H60, A0-A60 and B0-B30 Class divisions in marine and offshore construction for pipes and cables. Marine Firestop Putty is a non-hardening, moldable compound that can be handpacked into openings for permanent or temporary sealing. This product complies with International Maritime Organization (IMO) standards and is tested according to IMO resolution A.754 (18) and IMO FTP Code, Annex 1, Part 3 for A Rated deck and bulkhead divisions.