Sealed units are electric motors enclosed in a steel casing, and are commonly found in A/C units and refrigerators.  They are also called "compressors".  These units have a metal value due to their copper interiors.  You can view sealed unit prices here:  Sealed Unit Prices

When scrapping, ensure that oil is drained from the units.  Most scrap yards have price/lb for these units and others will pay a price/unit.