Revenue from Contracts with Customers

Revenue is recognized when control of the good or service is transferred to the customer either at a point in time or, in limited circumstances, as our services are rendered over time. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods or services. Sales, value add, and other taxes we collect concurrent with revenue-producing activities are excluded from revenue. Incidental items that are immaterial in the context of the contract are recognized as expense.

The following tables present sales to external customers by reportable segment.



	Three Months Ended September 30, 2019
	Life Sciences		Mobile Solutions		Power Solutions		Intersegment Sales Eliminations			Total
United States	$	79,429	$	40,147	$	38,750	$	(615	)	$	157,711
China	1,590		9,109		1,870		—			12,569
Brazil	—		9,414		72		—			9,486
Mexico	68		4,700		3,832		—			8,600
Germany	6,504		1,768		17		—			8,289
Switzerland	2,985		1,094		15		—			4,094
Other	3,435		6,839		2,874		—			13,148
Total net sales	$	94,011	$	73,071	$	47,430	$	(615	)	$	213,897



			Three Months Ended September 30, 2018
	Life Sciences		Mobile Solutions		Power Solutions		Intersegment Sales Eliminations			Total
United States	$	63,869	$	46,341	$	38,137	$	(567	)	$	147,780
China	2,405		11,111		1,696		—			15,212
Mexico	90		6,570		2,254		—			8,914
Germany	7,321		1,415		17		—			8,753
Brazil	—		8,200		107		—			8,307
Poland	2,107		1,215		6		—			3,328
Switzerland	—		1,420		47		—			1,467
Other	2,571		5,533		3,818		—			11,922
Total net sales	$	78,363	$	81,805	$	46,082	$	(567	)	$	205,683



			Nine Months Ended September 30, 2019
	Life Sciences		Mobile Solutions		Power Solutions		Intersegment Sales Eliminations			Total
United States	$	222,001	$	129,116	$	120,445	$	(1,602	)	$	469,960
China	5,155		27,580		5,306		—			38,041
Germany	23,836		4,490		54		—			28,380
Brazil	—		27,432		221		—			27,653
Mexico	312		15,144		10,776		—			26,232
Switzerland	9,759		3,606		56		—			13,421
Other	10,288		23,222		11,622		—			45,132
Total net sales	$	271,351	$	230,590	$	148,480	$	(1,602	)	$	648,819



			Nine Months Ended September 30, 2018
	Life Sciences		Mobile Solutions		Power Solutions		Intersegment Sales Eliminations			Total
United States	$	142,863	$	144,138	$	120,189	$	(1,798	)	$	405,392
China	3,843		34,273		4,140		—			42,256
Mexico	429		21,042		8,799		—			30,270
Brazil	29		27,722		157		—			27,908
Germany	11,138		4,500		24		—			15,662
Switzerland	3,827		3,915		35		—			7,777
Poland	1		5,485		23		—			5,509
Other	6,586		18,603		11,217		—			36,406
Total net sales	$	168,716	$	259,678	$	144,584	$	(1,798	)	$	571,180

Deferred Revenue

The following table provides information about contract liabilities from contracts with customers.



	Deferred Revenue
Balance at January 1, 2019	$	2,974
Balance at September 30, 2019	$	3,268

Revenue recognized during the three and nine months ended September 30, 2019, from amounts included in deferred revenue at the beginning of the period for performance obligations satisfied or partially satisfied during the period, was $1.4 million and $3.0 million, respectively.

Transaction Price Allocated to Future Performance Obligations

We are required to disclose the aggregate amount of transaction price that is allocated to performance obligations that have not yet been satisfied as of September 30, 2019, unless our contracts meet one of the practical expedients. Our contracts met the practical expedient for a performance obligation that is part of a contract that has an original expected duration of one year or less.

Sales Concentration

During the three months ended September 30, 2019, we recognized sales from a single customer of $23.7 million, or 11.1% of consolidated net sales. During the nine months ended September 30, 2019, we recognized sales from a single customer of $68.7 million, or 10.6% of consolidated net sales. Revenues from this customer are in our Life Sciences and Power Solutions groups. No customers represented more than 10% of our net sales during the three and nine months ended September 30, 2018.