In a continuing effort to streamline our business and align our business strategy for further integration of services and products, the Company committed to divest the business of our full range of permanent downhole monitoring systems and related services, which had been part of our Production Enhancement segment.

On June 7, 2019, we entered into a definitive purchase agreement for approximately $16.6 million in cash. A pre-tax gain of $8.3 million was recognized in connection with this transaction, subject to adjustments for working capital purposes and is classified as Income from discontinued operations in the consolidated statements of operations. The purchase agreement also provides for additional proceeds of up to $2.5 million based on the results of operations of the sold business in 2019 and 2020, none of which has been recognized. During the year ended December 31, 2020, we concluded final adjustments to the purchase agreement of $0.6 million, and we determined no additional proceeds based on the results of operations of the sold business in 2019. There are no other activities recorded in the consolidated statements of operations for the year ended December 31, 2020 and no balances recorded in the consolidated balance sheet for the discontinued operations as of December 31, 2020 and 2019.

The associated results of operations are separately reported as Discontinued Operations for all periods presented on the Consolidated Statements of Operations. As such, the results from continuing operations for the Company and segment highlights for Production Enhancement, exclude these discontinued operations.

Selected data for this discontinued business consist of the following (in thousands):

	For the Years Ended December 31,
	2020			2019		2018
Services	$	—		$	1,165	$	1,462
Product sales		—			4,233		5,708
Total revenue		—			5,398		7,170

Cost of services		—			690		1,163
Cost of product sales		—			3,196		5,696
Depreciation and amortization		—			—		115
Other expense (income)		—			91		72
Operating income		—			1,421		124
Gain (adjustment) on sale		(573	)		8,319		—
Income (loss) from discontinued operations before income tax		(573	)		9,740		124
Income tax expense (benefit)		(149	)		1,907		182
Income (loss) from discontinued operations	$	(424	)	$	7,833	$	(58	)

Net cash provided by operating activities of discontinued operations for the years ended December 31, 2019 and 2018 was $0.1 million and $0.2 million, respectively.

Net cash provided by (used in) investing activities of discontinued operations for the year ended December 31, 2020 and 2019 was $(0.2) million and $14.8 million, respectively.