8.	INTANGIBLE ASSETS

The intangible assets described in Note 7 are being amortized to cost of goods sold over their useful lives, which are estimated to be 10 years. Intangible amortization expense was $4,776 during the three-month periods ended September 30, 2018 and 2017 and $14,328 during the nine-month periods ended September 30, 2018 and 2017. The net value of these intangibles was $138,504 and $152,832 as of September 30, 2018 and December 31, 2017, respectively. A summary of intangible amortization expense estimated for the periods subsequent to September 30, 2018 is as follows:

Period	Amount
Three-month period ending December 31, 2018	$	4,776
Year ending December 31, 2019		19,104
Year ending December 31, 2020		19,104
Year ending December 31, 2021		19,104
Year ending December 31, 2022		19,104
After December 31, 2022		57,312
Total	$	138,504

Intangible assets as of September 30, 2018 consisted of the following:

	Gross Carrying Value		Accumulated Amortization			Net Book Value
Developed technology	$	184,100	$	(50,628	)	$	133,472
Customer relationships		1,300		(357	)		943
Non-compete agreements		5,640		(1,551	)		4,089
Total	$	191,040	$	(52,536	)	$	138,504

Intangible assets as of December 31, 2017 consisted of the following:

	Gross Carrying Value		Accumulated Amortization			Net Book Value
Developed technology	$	184,100	$	(36,820	)	$	147,280
Customer relationships		1,300		(260	)		1,040
Non-compete agreements		5,640		(1,128	)		4,512
Total	$	191,040	$	(38,208	)	$	152,832