The Company’s leases consist primarily of operating leases for administrative office spaces, research and development facilities, a manufacturing facility, and sales offices in various countries around the world. The Company determines if an arrangement is a lease at inception. Some lease agreements contain lease and non-lease components, which are accounted for as a single lease component. Total lease expense was approximately $374,000 for the three months ended March 31, 2019. Rent expense was approximately $286,000 for the three months ended March 31, 2018.

Initial lease terms are determined at commencement and may include options to extend or terminate the lease when it is reasonably certain the Company will exercise the option. Remaining lease terms range from one to seven years, some of which include options to extend for up to five years. Leases with an initial term of twelve months or less are not recorded on the condensed consolidated balance sheets. As the Company’s leases do not provide an implicit rate, the present value of future lease payments is determined using the Company’s incremental borrowing rate based on information available at commencement date.

The table below reconciles the undiscounted cash flows for the first five years and total of the remaining years to the operating lease liabilities recorded on the condensed consolidated balance sheet as of March 31, 2019 (in thousands):

	March 31,
	2019
2019 (remaining nine months)	$	1,783
2020		2,080
2021		1,603
2022		932
2023		636
Thereafter		237
Total minimum lease payments		7,271
Less: amount of lease payments representing interest		(1,132	)
Present value of future minimum lease payments		6,139
Less: current liabilities under operating leases		(2,067	)
Long-term operating lease liabilities	$	4,072

As of March 31, 2019, the weighted average remaining lease term for the Company’s operating leases is 3.9 years, and the weighted average discount rate used to determine the present value of the Company’s operating leases is 6.4%. Sublease rental income due in the future under non-cancelable subleases is $2.4 million.

Cash paid for amounts included in the measurement of operating lease liabilities was $0.5 million for the three months ended March 31, 2019. Cash received from sublease rentals was $0.2 million for the three months ended March 31, 2019.