In 2018, 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 in Income for 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.

The associated results of operations are separately reported as Discontinued Operations for all periods presented on the Consolidated Statements of Operations. Balance sheet items for this discontinued business, including an allocation of goodwill from the Production Enhancement segment, have been reclassified to Other current assets and Other current liabilities in the Consolidated Balance Sheet. Cash flows from this discontinued business are shown in the table below. 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 for the years ended December 31, 2019, 2018 and 2017 consisted of the following (in thousands):

	2019		2018			2017
Service revenue	$	1,165	$	1,462		$	1,254
Product sales		4,233		5,708			10,736
Total revenue		5,398		7,170			11,990

Cost of services, exclusive of depreciation expense shown below		690		1,163			709
Cost of product sales, exclusive of depreciation expense shown below		3,196		5,696			8,573
Depreciation and amortization		—		115			416
Other expense (income)		91		72			(180	)
Operating income		1,421		124			2,472
Gain on sale		8,319		—			—
Income from discontinued operations before income tax expense		9,740		124			2,472
Income tax expense		1,907		182			361
Income (loss) from discontinued operations, net of income taxes	$	7,833	$	(58	)	$	2,111

Selected data for this discontinued business at December 31, 2019 and 2018 consisted of the following (in thousands):

	2019		2018
Current assets	$	—	$	3,712
Non-current assets		—		1,848
Total assets	$	—	$	5,560

Current liabilities	$	—	$	1,633
Non-current liabilities		—		82
Total liabilities	$	—	$	1,715

Net cash provided by (used in) operating activities of discontinued operations for the years ended December 31, 2019, 2018 and 2017 was $0.1 million, $0.2 million and $2.5 million, respectively.

Net cash provided by investing activities of discontinued operations for the year ended December 31, 2019 was $14.8 million.