Actual internal dimensions used will depend on 3/4" x 1/2" internal corner posts so the usable area is 174mm x 75mm 6.8" x 2.9". But if you can knock out the corners in your project, the usable area is 192mm x 112mm 7.6" x 4.45". Inside height is 1.55 inches to the hem - minus the small risers, add just under 0.5 inches for the inside top. The small risers are 0.2" in diameter but can be sanded flat. Subtract 0.45" from the duct circumference if there are to be small risers.
Zulkit Junction Box ABS Plastic Waterproof IP65 Electrical Boxes Hinged Shell Outdoor Universal Project Enclosure With Mounting Plate And Wall Brackets Grey 11.8X7.9X6.3 Inch(300X200X160Mm)
10 Review
Junction Box, Zulkit Project Box IP65 Waterproof Dustproof ABS Plastic Electrical Boxes Electronic Enclosure Black 4.5 X 3.5 X 2.2 Inch(115 X 90 X 55 Mm)(Pack Of 1)
12 Review
⚡️ RVGUARD 50 Amp Weatherproof Outdoor Electrical Power Outlet Box - Lockable RV/EV NEMA 14-50R Receptacle Panel, 125/250V, ETL Listed
9 Review
Zulkit 5Pcs Black ABS Plastic Project Boxes - Ideal For Electrical And Power Junctions (80 X 50 X 21 Mm)
10 Review
⚡️ Sunpark LC-12014T (1) FC12T9 32W Circline (1) 2D 38W (1) FC16T9 40W Circline (1) FC9T9 30W Circline Lamp Compact Electronic Fluorescent Ballast with Circline Lamp Plug 120V
7 Review
Fulham WorkHorse WH2-120-C Adaptable Ballast - 2 Pack
3 Review
💡 Hydrofarm Quantum QT400 Dimmable Ballast for 400W Grow Lights
5 Review
💡 High-Quality Advance ICN-4P32-SC Electronic Fluorescent Ballast: Ideal for 4 Lamps, 32W T8, 120/277V
3 Review