This Metal boiler wrap with insulation is the style the Brand-new Amish built cooling unit use which is a heavy gauge metal, not the thin aluminum foil Norcold OEM coils used. This metal upgrade Boiler Wrap kit can be used to replace the OEM boiler pack. In some cases you may need to trim to fit. This is a minor issue. Most of the time if you ever have to have the AC electric heating elements replaced the old boiler pack will be damaged it may or may not be able to be repaired and must be replaced. Most of the time the RV tech will only just tape it back together. Norcold does have a metal boiler pack for the old 1200 series.