15. Leases

Operating lease expense for the year ended December 31, 2019, 2018 and 2017 was $1.0 million, $1.1 million and $1.1 million, respectively, and was included within Cost of sales, Engineering, design and product development expense, Selling and marketing expense, and General and administrative expense. Operating costs include short-term lease costs which were immaterial during the period.

The following information represents supplemental disclosure for the statement of cash flows related to operating leases (in thousands):

		Year Ended December 31, 2019
Operating cash outflows from leases		$	1,031

The following summarizes additional information related to our leases as of December 31, 2019:

	December 31, 2019
Weighted average remaining lease term (in years)		5.0
Weighted average discount rate		3.7	%

The maturity of the Company’s operating lease liabilities as of December 31, 2019 are as follows (in thousands):

	December 31, 2019
2020	$	1,042
2021		711
2022		434
2023		268
2024		273
Thereafter		616
Total undiscounted lease payments		3,344
Less imputed interest		295
Total lease liabilities	$	3,049

Prior to the adoption of ASC 842, rental commitments on an undiscounted basis were approximately $4.3 million at December 31, 2018 under non-cancelable operating leases and were payable as follows: $1.0 million in 2019; $1.0 million in 2020; $0.7 million in 2021; $0.4 million in 2022, $0.3 million in 2023 and $0.9 million thereafter.