3M™ Fire Barrier Moldable Putty Stix MP+ is a one-part, re-enterable, intumescent putty that can be easily formed to firestop through penetrations and blank openings in fire-rated assemblies. We formulated this dark red, easily moldable putty stick to provide up to 4 hours of fire protection. These putty stix also produce a draft and cold smoke seal and help reduce noise transfer.