Unique open cell foam in interlaced distribution is designed for superior sound absorption. It can stop the spread of sound wave and allow air flow through the ducting, perfect for reducing noise from fans and carbon filter systems.

Features:

• Two 4" flanged ends.
• Portable and light weight.
• Safe and effective operation.
• Easy to install and maintenance free.
• High-quality corrosion resistant galvanized sheet construction.
• Wave crest polyurethane sponge can offer excellent sound and vibration absorption.
• This high-performance sound absorbing foam lining can reduce 50% noise!
  If the noise of your fan/blower is 50db, our muffler can reduce it to 25db.
• Moisture resistant - great for use in damp environment.
• Extended collar and lip for easy duct hook-up.
• Air tight sealing tape pasted on the muffler

Specification:

Flange	4"
Fit for Fans/Blowers	4" Flange
Surface Material	Durable Galvanized Sheet
Sound Absorbing Foam	Wave Crest Polyurethane Sponge
Fusion Point of Foam	250 degree centigrade

The Influence to Hearing of Different Decibel:

Decibel	Sense of Hearing
0-20db	Very quiet, hardly feel
20-40db	Quiet, like soft voice
40-60db	General, like common talk indoor
60-70db	Noisy, bad for nerve
70-90db	Very noisy, nerve cells are damaged

Package Includes:

• 1x High-quality 4" Duct Muffler