Fire Stop Our Intumescent Letterbox Assemblies have been extensively tested to the latest British standards BS 476 parts 22 & 31.1 and have achieved a 32dB Rw rating on a BS EN ISO 240-3 acoustic test. 30 minute fire rating Fire tested to BS 476 part 22 Smoke tested to BS 476 part 31.1 Acoustic tested to BS EN ISO 240-3 achieving 32dB Rw Security PAS 23/24 Dimensions: 10”
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