A one-part, ready-to-use, re-enterable, intumescent putty that can be easily formed to firestop through penetrations and blank openings in fire-rated assemblies. Often used to fill voids in large openings and/or complex firestop systems. Provides up to 4-hours of fire protection. Dark red moldable putty stick. - Firestop tested up to 4 hours in accordance with ASTM E 814 (UL 1479) & CAN/ULC S115 - Provides draft and cold smoke seal - Often used to fill voids in large and/or complex firestop systems - Pliable and conformable (molds easily into required shapes) - Helps reduce noise transfer (STC-Rating of 56 when tested in STC 56-rated wall assembly) - Noncorrosive to metal and compatible with synthetic cable jackets - Will not dry out or crumble, re-enterable