The U.S. aircraft register, updated daily
Parts

Insulating Sleeve

No failure report names the insulating sleeve. 2 FAA approvals let 1 company make a replacement insulating sleeve, New Horizons holding the most (2).

Approved replacement parts 2 parts manufacturer approvals

A parts manufacturer approval (PMA) lets a company other than the aircraft's maker make a insulating sleeve and sell it as an approved part for the models named. These are the companies holding such approvals for a insulating sleeve:

MakerPartReplacesFitsGrantedStatus
New HorizonsInsulating Sleeve 9048151NH9048151CFM International CFM56 -2A, -2B, -2C2016-02-21current
New HorizonsInsulating Sleeve 9048151NH9048151CFM International CFM56 -2A, -2B, -2C2014-12-09current

Sources: the FAA's service difficulty reports since 1995 (a report is a part that failed and was fixed, as filed by an airline, repair station or owner; the count shows reporting as much as reliability) and the parts manufacturer approvals in the FAA's Dynamic Regulatory System. The part name is the reporters' and the approval holders' own words, reduced to the first plain words so that spellings meet.