Duct Fan Silencer 4 - Duct Fan Silencer for 4" Duct Fan ventilation (NOTE: Not compatible with MAC

(NOTE: Not compatible with MAC systems

User-selectable acid or alkaline relay

The pH level of soils or substrates strongly influences crop performance

RAW Classic Connoisseur 1¼ has everything you need to roll your own RAWthentic smokes in one easy-to-carry package

intense light coverage with its 8 passively cooled LED bars allowing you to use it in low rooms

Duct Fan Silencer 4 - Duct Fan Silencer for 4" Duct Fan ventilation (NOTE: Not compatible with MACA duct muffler designed for use with inline fans in grow tents, bathroom fans and other HVAC applications. Features dual aluminum flanges to help absorb sound waves from fan vibrations and airflow. High quality neoprene foam in an egg crate pattern that will reduce fan noise by up to 50%. Galvanized steel body that is corrosion resistant and can withstand extreme temperatures. Duct Opening Diameter: 4 inches Length: 15 inches Weight: 2. 30 pounds