- Product Information
Automatic Door Bottom Drop‑Down Seal
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Surface Finish Label
Art No. & Line Draw
Appearance Overview
Compliant with BHMA A156.22, NFPA80, NFPA101, ASTM E‑283, ASTM E‑90‑97, ASTM E1408‑91. Certified for fire‑rated, acoustic and exterior rain‑resistant door assemblies.
Application Scenarios
Hotel Guest Rooms
Concealed automatic drop‑down seal, block smoke, sound, drafts and light infiltration for hotel guest room doors.
Hospital & Nursing Facilities
Construction‑grade hardware for healthcare premises, acoustic insulation and smoke containment for patient areas.
Office & Government Buildings
Suited for new build or retrofitting existing wooden, metal, PVC and glazed doors, barrier‑free zero‑threshold compatible.
ADB‑349 : Width 19/32"(14.6mm) × Height 1‑3/8"(34.9mm). Length range:18"‑72"(457‑1829mm). Seal gap capacity up to 3/4"(19mm). Can shorten up to 2"(51mm) from lock‑side.
Warranty: 5‑year warranty
Custom Length: Cut‑to‑size service available
End Plates: Matching finish end plates optional
Concealed Installation: Recessed fitted into door bottom notch, fully hidden when door opens, preserves original door aesthetics. Seal only drops when door closes to reduce rubber wear.
Multi‑Performance Barrier: Blocks fire, smoke, sound up to 55dB, air drafts, dust, light and insect penetration. Certified driving‑rain resistance up to grade 9A for exterior doors.
Self‑Adjusting Mechanism: Parallel lowering action adapts to uneven or sloping floors, no floor dragging, reversible for left‑hand / right‑hand door installation.
Quick Installation & Retrofit: Simple mounting without complex door modification. Works for new construction and renovation projects, compatible for wood, metal, PVC, glazed doors.
Durable Construction: Alloy 6063‑TS extruded aluminium housing with sponge neoprene seal, maintenance‑free long‑term service life, reduces heat loss for energy saving.