The Company’s leases consist primarily of operating leases for administrative office space, 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 rent expense was approximately $0.4 million and $1.1 million for the three and nine months ended September 30, 2019, respectively. Rent expense was approximately $0.4 million and $1.l million for the three and nine months ended September 30, 2018, respectively.

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 the lease commencement date.

The table below reconciles the undiscounted cash flows for the first five years and the total of the remaining years to the operating lease liabilities recorded on the condensed consolidated balance sheet as of September 30, 2019 (in thousands):

	September 30,
	2019
2019 (remaining three months)	$	571
2020		2,109
2021		1,605
2022		934
2023		349
Thereafter		525
Total minimum lease payments		6,093
Less: amount of lease payments representing interest		(770	)
Present value of future minimum lease payments		5,323
Less: current liabilities under operating leases		(1,914	)
Long-term operating lease liabilities	$	3,409

As of September 30, 2019, the weighted average remaining lease term for the Company’s operating leases was 3.4 years, and the weighted average discount rate used to determine the present value of the Company’s operating leases was 6.4%. Sublease rental income due in the future under non-cancelable subleases was $2.1 million.

Cash paid for amounts included in the measurement of operating lease liabilities was $0.5 million and $1.6 million for the three and nine months ended September 30, 2019, respectively. Cash received from sublease rentals was $0.2 million and $0.6 million for the three and nine months ended September 30, 2019, respectively.