The Tenmat FF130E insulation protection cover is made from a fire-resistant material and is designed to keep insulation away from recessed light fixtures, as required by code. When installed with a foam sealant, it also stops air leakage through the fixture (the DOE estimates that recessed lights account for 50% of total thermal losses through ceilings). The covers are not meant for use in one- or two-hour fire-rated ceiling assemblies. They cost $15 each.
Tenmat USA, 302/633-6600, tenmatusa.com.