Operating Leases We lease certain offices, facilities, equipment and vehicles under non-cancellable operating and capital leases expiring at various dates through 2023. At December 31, 2016, future minimum contractual lease obligations were as follows: Years ending December 31,: Operating Leases 2017 $ 1,453 2018 1,455 2019 1,455 2020 1,455 2021 1,395 Thereafter 2,837 Total minimum lease payments $ 10,050 Rent expense for the years ended December 31, 2016 and 2015 was $1,440 and $1,447, respectively. Letters of Credit Certain customers could require us to issue standby letters of credit in the normal course of business to ensure performance under terms of contracts or as a form of product warranty. The beneficiary of a letter of credit could demand payment from the issuing bank for the amount of the outstanding letter of credit. Letters of credit outstanding at December 31, 2015 under the Eighth Amendment with Whitney were $0. Employment Agreements Certain of our Executives are employed under employment agreements containing severance provisions. In the event of termination of an Executives employment for any reason, the Executive will be entitled to receive all accrued, unpaid salary and vacation time through the date of termination and all benefits to which the Executive is entitled or vested under the terms of all employee benefit and compensation plans, agreements and arrangements in which the Executive is a participant as of the date of termination. In addition, subject to executing a general release in favor of the Company, the Executive will be entitled to receive certain severance payments in the event his employment is terminated by the Company other than for cause or by the Executive with good reason. These severance payments include: (i) a lump sum in cash equal to one to three times the Executives annual base salary; (ii) a lump sum in cash equal to one to two times the average annual bonus paid to the Executive for the prior two full fiscal years preceding the date of termination; (iii) a lump