Copy Records where records = "a" at Column B - Syntax Error

Hi All,
I want to copy records where records = "a" at Column B. What's wrong with this syntax?

Sheets("Sheet1").Range("B7:B" & ActiveSheet.UsedRange.Rows.Count).SpecialCells(xlCellTypeVisible).Value = "a".Copy

If on its own (without the copy), it is ok,

Sheets("Sheet1").Range("B7:B" & ActiveSheet.UsedRange.Rows.Count).SpecialCells(xlCellTypeVisible).Value = "a"

Regards,
Nironto