Lampholder SVCE Med Base Sngl (642, 680, 690, 561,
          661-2, 685-2, 695-2, 700T, 736T)
600 SeriesUse Starting w/Serial #2054736. Prior
          to Serial #2054736, see 7017485.
  561     Use Starting w/Serial #2054736. From
          Serial #1810000 to 2054736 see 7017485.
          Prior to Serial #1810000, see 3050010
          or 7016576.
600-2 SersUse Starting w/Serial #2054736. Prior
          to Serial #2054736, see 7017485.
  736T    Use Regardless of Serial Number
  700T    Use Starting With Serial #3151471
          Prior to #3151471 See 7016515