Removal of optional second Auxiliary Power Unit (APU) fire extinguisher system from 757-200 Series aircraft in accordance with FAA Approved Master Drawing List B57-26-002, Revision C, dated December 16, 2011, or later FAA approved revisions, and Instructions for Continued Airworthiness Report 11-126 Revision A, dated December 15, 2011, or later FAA accepted revisions. View PDF on drs.faa.gov ↗

The STC PDF is authoritative: installation instructions, ICA requirements and limitations.