The fixture you choose must be rated for use near insulation (IC housing rated) whenever ceiling insulation is present.

When a ceiling is uninsulated, a non-IC housing may be used.

If you have insulation in your ceiling, you need to select a box, either IB-702 or IB-703 with any of our remodelling housing units.  The box will provide added protection so that the electrical components due to not touch the insulation.

If you do not have insulation in your ceiling, you can choose the remodeilling or new construction housing directly.

Consult with your electrician if you are not sure whether you need to install a box.