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                                                Filed Pursuant to Rule 424(a)
                                                Registration No. 33-88808
 
                   PROSPECTUS SUPPLEMENT DATED MARCH 10, 1995
                                       TO
                 PRELIMINARY PROSPECTUS DATED FEBRUARY 23, 1995
 
     The Company believes that the worldwide demand for microfiltration products
in its markets is approximately $1.4 billion and is growing as a result of a
broadening base for filter applications, increasing concern for consumer safety,
a trend toward finer and more economical filtration, more stringent governmental
regulations and intensive research efforts to find cures for contagious, genetic
and other diseases. Management's strategy is to focus on geographic areas and
product applications in which microfiltration needs are expected to exceed
overall market growth. This growth strategy is being implemented by (a) focusing
on the Company's microfiltration products with competitive advantages and brand
name recognition; (b) strengthening the Company's international management team
and distributor network in order to build its presence in the growing
international marketplace; (c) marketing to large multinational companies the
benefits of purchasing their worldwide filtration requirements from a single
supplier; (d) accelerating new product development and introduction; and (e)
pursuing new market opportunities for the Company's microfiltration products.
The Company's internal projections reflect $200 million in sales in fiscal 1998
primarily as a result of growth in international sales. The Company believes
that its existing manufacturing facilities can accommodate this sales growth.
See "Investment Considerations" and "Management's Discussion and Analysis of
Financial Condition and Results of Operations," as well as the other information
included elsewhere herein or incorporated herein by reference, which prospective
investors should consider prior to purchasing shares of the Common Stock offered
hereby. In addition to sales growth, management has been implementing a strategy
to increase profitability by (i) reducing product scrap and waste; (ii)
increasing automation to reduce labor content; (iii) consolidating suppliers to
improve the quality and reduce the cost of purchased materials; (iv) targeting
sales efforts on high margin microfiltration products and membranes; and (v)
increasing capacity utilization.
 
     The Company is a Michigan corporation with its executive offices at 600
South Wagner Road, Ann Arbor, Michigan 48103-9019; telephone (313) 665-0651.
 
                                  THE OFFERING
 
                                              
Common Stock Offered........................     1,000,000 shares
Common Stock to be Outstanding after the
  Offering..................................     7,218,969 shares(1)
Use of Proceeds.............................     Repayment of certain indebtedness
American Stock Exchange Symbol..............     GSC


 
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(1) Does not include 782,296 shares of Common Stock issuable upon the exercise
    of outstanding stock options and warrants at January 31, 1995. See Note F to
    the Consolidated Financial Statements.
 
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                   PROSPECTUS SUPPLEMENT DATED MARCH 10, 1995
                                       TO
                 PRELIMINARY PROSPECTUS DATED FEBRUARY 23, 1995

microfiltration products. The Company's internal projections reflect $200
million in sales in fiscal 1998 primarily as a result of growth in international
sales. The Company believes that its existing manufacturing facilities can
accommodate this sales growth. See "Investment Considerations" and "Management's
Discussion and Analysis of Financial Condition and Results of Operations," as
well as the other information included elsewhere herein or incorporated herein
by reference, which prospective investors should consider prior to purchasing
shares of the Common Stock offered hereby. In addition to sales growth,
management has been implementing a strategy to increase profitability by (i)
reducing product scrap and waste; (ii) increasing automation to reduce labor
content; (iii) consolidating suppliers to improve the quality and reduce the
cost of purchased materials; (iv) targeting sales efforts on high margin
microfiltration products and membranes; and (v) increasing capacity utilization.
 
PRODUCT AND MARKET OVERVIEW
 
     Filtration is the process of separating particles of various sizes from
liquids or gases, including (a) macrofiltration, for the separation of
large-size particles visible to the naked eye (a grain of sand); (b)
microfiltration, for the separation and removal of microscopic-sized particles
(bacteria); and (c) reverse osmosis, for separation at the molecular level
(desalination of saltwater). A filtration device consists of a plastic or metal
housing and a filtration medium. Filtration media, which can be manufactured out
of a variety of substances, act as the separator or barrier in the filtration
process.
 
     Of the filtration processes, microfiltration has the most diverse
applications. Microfiltration utilizes several different types of filtration
media, including microporous and nylon membranes, glass fibers and ceramics.
Microporous membranes are thin, film-like materials with millions of microscopic
holes per square inch. These membranes are the most popular microfiltration
media because they offer the following benefits: (i) removal of
specifically-sized particles, (ii) configuration into a variety of shapes and
sizes of filtration devices, and (iii) incorporation into economical, disposable
filtration devices.
 
     The Company believes that worldwide demand for microfiltration products in
its markets is $1.4 billion, two-thirds of which is from outside the United
States. It is expected that the growth rate for sales of microfiltration
products internationally will exceed that of the United States over the next
several years, particularly in the Asia/Pacific Rim and Latin America. Growth
opportunities in the Asia/Pacific Rim and Latin America should result primarily
from increasing industrialization, the effects of government regulations and
environmental concerns. Sales in Western Europe are growing primarily due to
microfiltration demands from biotechnology, pharmaceutical and healthcare
companies.
 
     The demand for microfiltration products in the United States is growing due
to (a) a broadening base for filter applications, (b) increasing concern for
consumer safety, (c) a trend toward finer and more economical filtration, (d)
more stringent governmental regulations and (e) intensive research efforts to
find cures for contagious, genetic and other diseases. In addition, demand is
increasing for biomedical and diagnostic membranes for routine sterilization,
cell cultures, protein separation and diagnostic tests.
 
GROWTH STRATEGY
 
     The Company's strategy is to expand its position as a manufacturer of
microfiltration products to the biotechnology/pharmaceutical,
medical/healthcare, high technology manufacturing and environmental markets by
responding to customer needs with high quality products at competitive prices.
Management expects to increase sales in excess of market growth by increasing
international sales, expanding sales to existing customers, introducing new
products and entering new markets with microfiltration products. The Company is
implementing these sales and marketing strategies and making the infrastructure
investments necessary to achieve the expected growth.
 
     The Company's growth strategy focuses on the following key factors:
 
     Key Products with Competitive Advantages and Brand Name Recognition. The
Company is focusing its sales and marketing programs on those microfiltration
products which have competitive advantages and brand name recognition. The
Company has targeted these products because of their ease of use, novel and
unique design and superior performance characteristics.
 
     International Sales Growth. Historically, the Company's worldwide sales
have been divided approximately 65% U.S. and 35% international. The Company
believes, however, that the worldwide market for microfiltration products is
approximately 35% U.S. and 65% international. The Company's historical sales mix
 
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