How to choose the size of halogen frame for halogen cutout

ZEM ceiling halogens are designed and manufactured in two types of recessed and surface.

recessed ceiling halogens:

The meaning of recessed ceiling halogens is that the frame of the halogen frame is placed by two springs inside the ceiling girder, which are cut in different dimensions.

ZEM ceiling halogen diffusers are from size 4 to size 19.5 cm, which includes a wide range of dimensions.
The thing that should be considered when choosing a halogen frame is that the outer diameter of the halogen frame is larger than the diameter of the ceiling cut out.
For example, the external diameter of the classic Sienna ceiling halogen frame is 10 cm and it can cover both size 6 and size 8 cutout.

Round 6cm and 8cm
In the following, we will see some models of halogen frames with different cutout.