<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONDENSED CONSOLIDATED BALANCE SHEETS AT JUNE 30, 1998 AND 1997 (UNAUDITED) AND
THE CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND CASH FLOWS FOR THE SIX
MONTHS ENDED JUNE 30, 1998 AND 1997 (UNAUDITED) AND IS QUALIFIED IN ITS ENTIRETY
BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
       
                                                  
<PERIOD-TYPE>                   6-MOS                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1998
<PERIOD-END>                               JUN-30-1997             JUN-30-1998
<CASH>                                       3,651,237               5,527,946
<SECURITIES>                                         0                       0
<RECEIVABLES>                                7,550,577               7,914,478
<ALLOWANCES>                                   165,466                 174,250
<INVENTORY>                                  3,059,293               3,205,945
<CURRENT-ASSETS>                            15,301,823              17,536,675
<PP&E>                                      14,339,366              15,978,121
<DEPRECIATION>                               7,708,120               8,411,122
<TOTAL-ASSETS>                              33,182,031              39,130,212
<CURRENT-LIABILITIES>                        5,829,760               6,297,136
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                        34,566                  34,886
<OTHER-SE>                                  26,533,136              31,581,029
<TOTAL-LIABILITY-AND-EQUITY>                33,182,031              39,130,212
<SALES>                                     29,247,471              31,850,428
<TOTAL-REVENUES>                            29,247,471              31,850,428
<CGS>                                       16,393,117              17,986,013
<TOTAL-COSTS>                                9,120,448               9,697,603
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                            (35,371)                (56,729)
<INCOME-PRETAX>                              3,829,125               4,234,265
<INCOME-TAX>                                 1,523,993               1,685,238
<INCOME-CONTINUING>                                  0                       0
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                 2,305,132               2,549,027
<EPS-PRIMARY>                                      .67                     .73
<EPS-DILUTED>                                      .66                     .71