Operating leases consist of office space, automobiles and various other equipment in the U.S. and in certain international locations in which we do business. Other contracts, such as manufacturing agreements and service agreements, are reviewed to determine if they contain any embedded leases. As of March 31, 2020, the operating leases had remaining lease terms of one month to five years, some of which include options to extend the leases for up to nine years, and some of which include options to terminate the leases within three months. As of March 31, 2020 and December 31, 2019, the Company’s operating lease assets and operating lease liabilities were as follows:

(In thousands)	Classification	March 31, 2020		December 31, 2019
Assets
Operating lease asset	Other assets	$	7,474	$	8,452
Total lease asset		$	7,474	$	8,452

Liabilities
Current operating lease liability	Accrued expenses	$	2,506	$	2,676
Non-current operating lease liability	Other non-current liabilities		5,012		5,818
Total lease liability		$	7,518	$	8,494

Lease expense related to short-term leases (initial term of less than 12 months) was $9 thousand and $0.2 million for the three months ended March 31, 2020 and 2019, respectively, and was included in cost of sales, selling, general and administrative expenses and research and development expenses in the Condensed Consolidated Statements of Income (Loss). Lease expense related to variable lease payments that do not depend on an index or rate, such as real estate taxes and insurance reimbursements, was $0.2 million and $0.1 million for the three months ended March 31, 2020 and 2019, respectively.

Components of lease expense included in the Condensed Consolidated Statements of Income (Loss) for the three months ended March 31, 2020 and 2019 were as follows:

	Three Months Ended
	March 31,
(In thousands)	2020		2019
Selling, general and administrative expenses	$	327	$	349
Research and development expenses		425		454
Cost of sales		21		16
Total operating lease expense	$	773	$	819

As of March 31, 2020 and December 31, 2019, operating lease liabilities included on the Condensed Consolidated Balance Sheets by future maturity were as follows:

(In thousands)	March 31, 2020			December 31, 2019
2020	$	2,066		$	2,856
2021		2,326			2,412
2022		1,630			1,705
2023		1,076			1,160
2024		468			482
Thereafter		259			264
Total lease payments		7,825			8,879
Less: Interest		(307	)		(385	)
Present value of lease liabilities	$	7,518		$	8,494

Future operating lease payments include $0.6 million related to options to extend lease terms that are reasonably certain of being exercised. There are no legally binding leases that have not yet commenced.

An incremental borrowing rate is used based on information available at the commencement date in determining the present value of lease payments. The incremental borrowing rate was determined on a portfolio basis by grouping leases with similar terms as well as grouping leases based on a U.S. dollar or Euro functional currency. The actual rate is then determined based on a credit spread over LIBOR as well as the Bloomberg Curve Matrix for the U.S. Communications section. The following table provides information about the weighted average lease terms and weighted average discount rates as of March 31, 2020:

	As of March 31, 2020
Weighted average remaining lease term (in years)
Operating leases with USD functional currency		2.2
Operating leases with Euro functional currency		4.2
Weighted average discount rate
Operating leases with USD functional currency		3.87	%
Operating leases with Euro functional currency		1.83	%

	Three Months Ended
	March 31,
(In thousands)	2020		2019
Cash paid for amounts included in the measurement of operating lease assets / liabilities
Cash used in operating activities related to operating leases	$	707	$	811
Right-of-use assets obtained in exchange for lease obligations	$	85	$	10,387

We are the lessor in sales-type lease arrangements for network equipment, which have initial terms of up to five years, and consisted of the following as of March 31, 2020 and December 31, 2019

(In thousands)	March 31, 2020		December 31, 2019
Current minimum lease payments receivable⁽¹⁾	$	1,049	$	1,201
Non-current minimum lease payments receivable⁽²⁾		715		889
Total minimum lease payments receivable		1,764		2,090
Less: Current unearned revenue		298		365
Less: Non-current unearned revenue		124		163
Net investment in sales-type leases	$	1,342	$	1,562

Components of gross profit related to sales-type leases recognized at the lease commencement date and interest and dividend income included in the Condensed Consolidated Statements of Income (Loss) for the three months ended March 31, 2020 and 2019 were as follows:

	Three Months Ended
	March 31,
(In thousands)	2020		2019
Sales - Network Solutions	$	38	$	1,512
Less: Cost of sales - Network Solutions		16		591
Gross profit	$	22	$	921

Interest and dividend income	$	13	$	87