Content Container Nailor 6600 and 66UNI Series Ceiling Diffusers have been designed to satisfy both architectural and engineering criteria. The clean uncluttered face panel design compliments any decor, blending beautifully with virtually any architectural style or requirement. Models 6600 - Square Neck • Adjustable Face 6600-O - Square Neck • Adjustable Face • with OBD 66UNI - 66UNI • Round Neck • Perimeter Slot Submittals All Submittals Combined Individual Submittals 6600(-O) • Steel • Adjustable Plaque Face • Ceiling Module 24"x 24" • Round Neck 66UNI • Steel • Plaque Face • with Perimeter Slots • Ceiling Module 24"x 24" • Round Neck Options and Accessories 4250 • Air Balancing Device • Radial Sliding Blade Damper • Steel • for Round Neck Diffusers 4275 • Air Balancing Device • Radial Opposed Blade Damper • Steel • for Round Neck Diffusers • 5-16" diameter 4675 • Air Balancing Device • Butterfly Damper • Steel • for Round Neck Diffusers SR, SR-O • Square to Round Transition Collars • Steel • Diffuser Accessory Performance Data 6600 • Square Neck 66UNI • 24 x 24 (610 x 610) Ceiling Module Finish Finishes for Grilles, Registers & Diffusers Woodgrain Finish Brochure Catalog