Recessed screwdriver operated Opposed Blade Damper
Adjustable baffles to control air flow through diffuser
Premium 3" round collar with bead (700DVD-3in)
Non-standard size collar (available in 6" through 20")
NGD - Narrow ceiling grid dimples for 9/16" T-Rails, changes O.D. to 23 29/32"
TVB - Thermal Vapor Blanket (R6)