Drain Trough, SVCE (601R, 650, 501R, 550)
     601R Use Prior to Serial #1810000.
          Starting With #1810000 See 7016926.
     650  Use Prior to Serial #1810000.
          Starting With #1810000 See 7016926.
     501R Use Regardless of Serial Number
     550  Use Regardless of Serial Number