DISTRICT DIRECTOR
G.P.O. BOX 1680
BROOKLYN, NY 11202                            Employer Identification Number:
                                                       06-1159240
                                              File Folder Number:
Date:  31 DEC 1996                                     063004725
                                              Person to Contact:
CUNO INCORPORATED                                      JOHN LILJEHULT
100 RESEARCH PARKWAY                          Contact Telephone Number:
MERIDEN, CT 06450                                      (718) 488-2411
                                              Plan Name:
                                                 CUNO INC SAVINGS AND RETIREMENT
                                                 PLAN
                                              Plan Number:  008

Dear Applicant:

         We have made a favorable  determination on your plan, identified above,
based on the  information  supplied.  Please keep this letter in your  permanent
records.

         Continued  qualification of the plan under its present form will depend
on its  effect in  operation.  (See  section  1.401-1(b)(3)  of the  Income  Tax
Regulations.) We will review the status of the plan in operation periodically.

         The enclosed  document  explains  the  significance  of this  favorable
determination  letter,  points out some  features  that may affect the qualified
status  of your  employee  retirement  plan,  and  provides  information  on the
reporting  requirements  for your  plan.  It also  describes  some  events  that
automatically nullify it. It is very important that you read the publication.

         This letter  relates only to the status of your plan under the Internal
Revenue Code. It is not a determination regarding the effect of other federal or
local statutes.

         This determination letter is applicable for the plan adopted on October
1, 1996.

         This plan  satisfies the  nondiscrimination  in amount  requirement  of
section  1.401(a)(4)-1(b)(2)  of the  regulations on the basis of a design-based
safe harbor described in the regulations.

         This  letter  is issued  under  Rev.  Proc.  93-39  and  considers  the
amendments  required by the Tax Reform Act of 1986 except as otherwise specified
in this letter.

         This  plan  satisfies  the   nondiscriminatory   current   availability
requirements  of section  1.401(a)(4)-4(b)  of the  regulations  with respect to
those  benefits,  rights,  and  features  that are  currently  available  to all
employees in the plan's  coverage group.  For this purpose,  the plan's coverage
group consists of those employees  treated as currently  benefiting for purposes
of demonstrating  that the plan satisfies the minimum  coverage  requirements of
section 410(b) of the Code.

         This letter may not be relied upon with respect to whether the plan




CUNO INCORPORATED                        -2-


satisfies  the  qualification  requirements  as  amended  by the  Uruguay  Round
Agreements Act, Pub. L. 103-465.

         We have sent a copy of this letter to your  representative as indicated
in the power of attorney.

         If you have questions concerning this matter, please contact the person
whose name and telephone number are shown above.

                                                     Sincerely yours,

                                                     /s/ Herbert J. Huff

                                                     Herbert J. Huff
                                                     District Director

Enclosures:
Publication 794
Reporting & Disclosure Guide
  for Employee Benefit Plans