The PET Shows three parts but they all end up being the same number:
i) 911-542-905-00 for the top channel
ii) 911-542-905-00 (same as #i) for the front channel
iii) 911-542-905-00 (same as #i & #ii) for the rear channel
when this it plugged into the Pelican, it shows on the link below as #27
http://www.pelicanparts.com/cgi-bin/ksearch/PEL_search.cgi?command=show_part_page&please_wait=N&make=POR&model=911E§ion=BDYsl2&page=1&bookmark=3&part_number=911-542-905-00-M260