The following tables present our revenues by sales type as presented in our condensed consolidated statements of operations disaggregated by the timing of transfer of goods or services (in thousands, unaudited):


	For the Three Months Ended September 30,
	2019		2018
Product sales
Product transferred to customers at a point in time	$	63,641	$	75,817
Product transferred to customers over time	—		—
	$	63,641	$	75,817


	For the Nine Months Ended September 30,
	2019		2018
Product sales
Product transferred to customers at a point in time	$	200,434	$	222,118
Product transferred to customers over time	—		—
	$	200,434	$	222,118


	For the Three Months Ended September 30,
	2019		2018
Service sales
Service transferred to customers at a point in time	$	12,526	$	11,580
Service transferred to customers over time	14,349		12,308
	$	26,875	$	23,888


	For the Nine Months Ended September 30,
	2019		2018
Service sales
Service transferred to customers at a point in time	$	36,960	$	30,939
Service transferred to customers over time	40,230		37,726
	$	77,190	$	68,665

The following table presents our revenues disaggregated by geography, based on the billing addresses of our customers (in thousands, unaudited):


	For the Three Months Ended September 30,
	2019		2018
Total sales to external customers
United States	$	37,166	$	38,090
EMEA ⁽¹⁾	26,424		29,577
Other APAC ⁽¹⁾	16,120		16,602
China	7,751		11,340
Other Americas ⁽¹⁾	3,055		4,096
	$	90,516	$	99,705


	For the Nine Months Ended September 30,
	2019		2018
Total sales to external customers
United States	$	108,174	$	115,670
EMEA ⁽¹⁾	87,554		88,858
Other APAC ⁽¹⁾	46,550		48,502
China	25,007		26,973
Other Americas ⁽¹⁾	10,339		10,780
	$	277,624	$	290,783

⁽¹⁾Regions represent Europe, the Middle East, and Africa (EMEA); Asia-Pacific, excluding China (Other APAC); and Canada, Mexico, and Brazil (Other Americas).