Have question about using .find statement and brackets around After:= statement

I am reviewing some code and i found this .find statement.

    fnd_frst_data_row = input_wrksht.Cells.Find(What:="*", After:=[Study_col_Header1], SearchOrder:=xlByColumns, SearchDirection:=xlNext).Row

I am confused about the following:

After:=[Study_col_Header1]


whats up with the "[]" brackets?