Volume Damper Low-Leak OBD 3000-0BDLL-48X20 Step Down Ceiling Diffuser 3 hour fire resistance rating

3 hour fire resistance rating

Heavy duty steel honeycomb construction

w/ Screwdriver Operated Opposed Blade Damper

Standard Features * Single plaque ceiling diffuser * 360 air diffusion * Hinged-down core for easy duct access * No Labor Collar * Seismic support hangers * Available sizes: 6"-10"

165° replaceable fusible link (#50)

Volume Damper Low-Leak OBD 3000-0BDLL-48X20 Step Down Ceiling Diffuser 3 hour fire resistance ratingh3. Standard Features * Opposed blade operation for precise volume control * 16 gauge galvanized channel frame * Blades are vee stiffened 16 gauge galvanized for strength and stability * Blades pivot on non metallic celcon bushings * 1 2" square zinc plated steel pivot pins * 1 2" square zinc plated steel adjustable operating shaft extending up to 4" beyond the air control frame * Single blades on dampers with a height of 12" or less * Mill finish h3.