Condensed Consolidated Statements Of Income (USD $) In Thousands, except Per Share data	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenues:
Products	$ 114,479	$ 122,188	$ 234,663	$ 244,021
Services	22,515	19,812	39,998	40,512
Total revenues	136,994	142,000	274,661	284,533
Cost and expenses:
Products	68,585	66,539	135,506	135,931
Services	13,415	13,010	26,607	25,433
Total cost of sales	82,000	79,549	162,113	161,364
Selling, general and administrative	16,037	16,077	34,298	29,510
Engineering and product development	8,529	7,051	17,227	13,837
Special item				5,901
Total costs and expenses	106,566	102,677	213,638	210,612
Operating income	30,428	39,323	61,023	73,921
Interest income	86	69	185	130
Interest expense	(11)	(11)	(22)	(38)
Income before income taxes	30,503	39,381	61,186	74,013
Income tax provision	8,295	11,383	17,306	20,318
Net income	$ 22,208	$ 27,998	$ 43,880	$ 53,695
Earnings per common share:
Basic	$ 0.55	$ 0.70	$ 1.10	$ 1.35
Diluted	$ 0.55	$ 0.70	$ 1.09	$ 1.34
Weighted average common shares outstanding:
Basic	40,058	39,819	40,054	39,774
Diluted	40,312	40,023	40,316	39,994

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