Premium 12v Fixed IP65 Fire Rated Downlight

will this design be suitable for existing 90 mm cut outs?
The cutout for this fitting is 70mm. 90mm would require a larger downlight. Product Ref: 7222 is perfect.

What is the outside diameter of this light?And what size is the hole required for it to fit into? does it come with a dimmable driver? can you do them in polished brass?
The overall diameter is 100mm, Requires a 70mm cut-out. It does not come with a transformer, The one we recommed is dimmable when used with dimmable lamps. They are only available in polished chrome. Mains alternative, Tilt option is available in polished brass, This can be found here.. Product Ref: 6243

My original cut out is 75mm. Will these still be okay to use as a replacement to my existing fitting?
Yes, the fixings that hold this downlight in the ceiling will work in a 75mm cutout.

Hi, do you know if you can use LED lamps with this downlight? And then you do not need a transformer correct?
You can use an MR16 LED Lamp in these, however these fittings are Low Voltage and still require a transformer even if an MR16 LED lamp is used.

At 116mm, the unit is relatively deep. Does it have any minimum requirement for clear space above it, please? My ceiling is 15mm, and the recess 155mm, which would leave 54mm above. Thank you.
116mm is the full height of the fixture. Take off the 3mm bezel and the 15mm plasterboard and the fixture uses 98mm of your void. You have plenty of room for ventilation.

What size cut-out is it, 70mm?
Yes it is a 70mm cut-out.

Do the lights come with the transformer required for them to be low voltage?
This low voltage fitting requires a transformer. It`s not supplied. Scroll to the bottom of the page for the relevant transformer.