def _replace_names(input_list, instr='sci', outstr='red'):

    """Replace ``instr`` with ``outstr`` in every element of ``input_list``.

    """

    instr += '.fits'
    outstr += '.fits'

    for n in range(len(input_list)):
        input_list[n] = input_list[n].replace(instr, outstr)

    return input_list