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                                  Exhibit 31.1

                            CERTIFICATION PURSUANT TO
                                RULE 15d-14(a) OF
                       THE SECURITIES EXCHANGE ACT OF 1934
                             AS ADOPTED PURSUANT TO
                  SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Michael A. McLain, certify that:

1.       I have reviewed this quarterly report on Form 10-Q/A of Aearo Company
         I;

2.       Based on my knowledge, this report does not contain any untrue
         statement of a material fact or omit to state a material fact necessary
         to make the statements made, in light of the circumstances under which
         such statements were made, not misleading with respect to the period
         covered by this report;

3.       Based on my knowledge, the financial statements, and other financial
         information included in this report, fairly present in all material
         respects the financial condition, results of operations, and cash flows
         of the registrant as of, and for, the periods presented in this report;

4.       The registrant's other certifying officers and I are responsible for
         establishing and maintaining disclosure controls and procedures (as
         defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
         registrant and we have:

                           a) designed such disclosure controls and procedures,
                  or caused such disclosure controls and procedures to be
                  designed under our supervision, to ensure that material
                  information relating to the registrant is made known to us by
                  others within those entities, particularly during the period
                  in which this report is being prepared;

                           b) evaluated the effectiveness of the registrant's
                  disclosure controls and procedures and presented in this
                  report our conclusions about the effectiveness of the
                  disclosure controls and procedures, as of the end of the
                  period covered by this report based on such evaluation; and

                           c) disclosed in this report any change in the
                  registrant's internal control over financial reporting that
                  occurred during the registrant's most recent fiscal quarter
                  that has materially affected, or is reasonably likely to
                  materially affect, the registrant's internal control over
                  financial reporting;

5.       The registrant's other certifying officers and I have disclosed, based
         on our most recent evaluation of internal control over financial
         reporting, to the registrant's auditors and the audit committee of the
         registrant's board of directors (or persons performing the equivalent
         function):

                           a) all significant deficiencies and material
                  weaknesses in the design or operation of internal control over
                  financial reporting which are reasonably likely to adversely
                  affect the registrant's ability to record, process, summarize
                  and report financial information; and

                           b) any fraud, whether or not material, that involves
                  management or other employees who have a significant role in
                  the registrant's internal control over financial reporting.


Date:  November 21, 2005              /s/ Michael A. McLain
                                      ---------------------
                                      Michael A. McLain
                                      Chairman, President and Chief Executive
                                      Officer