On a refurbishment the hole is fixed. Everything else negotiates around it.
A Ø95 mm cut-out fitting can be 102 mm across on a bordered trim or 125 mm across on a borderless flange. The bordered figure is what you see; the borderless figure is what has to clear obstructions above the ceiling. Both are listed on every product page here.
A trim ring laps the cut and hides 4–5 mm of rough edge per side, which is why refurbishments almost always use bordered fittings. Borderless assumes the ceiling will be plastered around the flange — a new-build decision, not a retrofit one.
Plenum depth kills more specifications than diameter. The catalogue answers this directly: WA02 bodies are shallower than WA01 at the same cut-out and wattage (92.5 mm against 116 mm at Ø95 mm, both 30 W), and the DL830 SMD downlights are 47–58 mm deep.
Round cut-outs across this catalogue run Ø35, Ø45, Ø47, Ø55, Ø65, Ø75, Ø80, Ø90, Ø95, Ø115, Ø120, Ø155, Ø175 and Ø205 mm. Square and rectangular cut-outs run 55×55 to 317×102 mm.
Send us the room and the ceiling and we will tell you what we would specify and why.
