23. Commitments and Contingencies Total rent expense for the three years ended December 31, 2018 was as follows (in thousands): Total Real Estate Other 2018 $ 12,605 $ 9,272 $ 3,333 2017 11,954 8,983 2,971 2016 10,171 7,550 2,621 At December 31, 2018, we are obligated to make minimum rental payments through 2028, under operating leases, which are as follows (in thousands): 2019 $ 8,483 2020 7,382 2021 6,753 2022 5,763 2023 5,278 Thereafter 10,590 Total $ 44,249 Warranties We generally warrant our products against certain manufacturing and other defects. These product warranties are provided for specific periods of time depending on the nature of the product. As of December 31, 2018 and 2017, we have accrued $19.6 million and $20.9 million, respectively, for estimated product warranty claims included in accrued customer returns. The accrued product warranty costs are based primarily on historical experience of actual warranty claims. Warranty expense for each of the years 2018, 2017 and 2016 were $85.9 million, $94.4 million and $99.1 million, respectively. T he following table provides the changes in our product warranties: December 31, 2018 2017 (In thousands) Balance, beginning of period $ 20,929 $ 24,072 Liabilities accrued for current year sales 85,850 94,367 Settlements of warranty claims (87,143 ) (97,510 ) Balance, end of period $ 19,636 $ 20,929 Letters of Credit At December 31, 2018, we had outstanding letters of credit with certain vendors aggregating approximately $3.1 million. These letters of credit are being maintained as security for reimbursements to insurance companies and as security to the landlord of our administrative offices in Long Island City, New York. The contract amount of the letters of credit is a reasonable estimate of their value as the value for each is fixed over the life of the commitment. Change of Control Arrangements We have a change in control arrangement with one key officer. In the event of a change of control (as defined in the agreement), the executive will receive severance payments and certain other benefits as provided in his agreement. Asbestos In 1986, we acquired a brake business, which we subsequently sold in March 1998 and which is accounted for as a discontinued operation in the accompanying statement of operations. When we originally acquired this brake business, we assumed future liabilities relating to any alleged exposure to asbestos-containing products manufactured by the seller of the acquired brake business. In accordance with the related purchase agreement, we agreed to assume the liabilities for all new claims filed on or after September 2001. Our ultimate exposure will depend upon the number of claims filed against us on or after September 2001, and the amounts paid for settlements, awards of asbestos-related damages, and defense of such claims. At December 31, 2018, approximately 1,430 cases were outstanding for which we may be responsible for any related liabilities. Since inception in September 2001 through December 31, 2018, the amounts paid for settled claims are approximately $25.6 million. We do not have insurance coverage for the indemnity and defense costs associated with the claims we face. In evaluating our potential asbestos-related liability, we have considered various factors including, among other things, an actuarial study of the asbestos related liabilities performed by an independent actuarial firm, our settlement amounts and whether there are any co-defendants, the jurisdiction in which lawsuits are filed, and the status and results of such claims. As is our accounting policy, we consider the advice of actuarial consultants with experience in assessing asbestos-related liabilities to estimate our potential claim liability. In addition, based on the information contained in the actuarial study and all other available information considered by us, we have concluded that no amount within the range of settlement payments was more likely than any other and, therefore, in assessing our asbestos liability we compare the low end of the range to our recorded liability to determine if an adjustment is required. The methodology used to project asbestos-related liabilities and costs in our actuarial study considered: (1) historical data available from publicly available studies; (2) an analysis of our recent claims history to estimate likely filing rates into the future; (3) an analysis of our currently pending claims; and (4) an analysis of our settlements to date in order to develop average settlement values. In accordance with our policy of performing an annual actuarial evaluation in the third quarter of each year, and whenever events or changes in circumstances indicate that additional provisions may be necessary, an actuarial study were performed as of August 31, 2018. The results of the August 31, 2018 study included an estimate of our undiscounted liability for settlement payments and awards of asbestos-related damages , excluding legal costs and any potential recovery from insurance carriers, ranging from $37.1 million to $56.9 million for the period through 2061. Based upon the results of the August 31, 2018 actuarial study, in September 2018 we increased our asbestos liability to $37.1 million, the low end of the range, and recorded an incremental pre-tax provision of $3.5 million in earnings (loss) from discontinued operations. In November 2018, we were involved in an asbestos liability case in California, in which a jury returned a verdict in favor of the plaintiff for the gross amount of $8.6 million in compensatory damages. Of this amount, we were held responsible for approximately $7.4 million, and we plan to pursue all rights of appeal. As a result of this asbestos case, our actuarial firm revised the results of the August 31, 2018 study. The results of the revised actuarial study increased the low end of the estimated range of our undiscounted liability for settlement payments and awards of asbestos-related damages, excluding legal costs and any potential recovery from insurance carriers, from $37.1 million to $46.7 million, and increased the high end of the range from $56.9 million to $83.9 million for the period through 2061. Based upon the results of the revised actuarial study, in December 2018, and in accordance with our practice, we increased our asbestos liability to $46.7 million, the low end of the range, and recorded an additional incremental pre-tax provision of $10.1 million in earnings (loss) from discontinued operations. Future legal costs, which are expensed as incurred and reported in earnings (loss) from discontinued operations, are estimated, according to the revised study, to range from $45 million to $83.1 million. We plan to perform an annual actuarial evaluation during the third quarter of each year for the foreseeable future and whenever events or changes in circumstances indicate that additional provisions may be necessary. Given the uncertainties associated with projecting such matters into the future and other factors outside our control, we can give no assurance that additional provisions will not be required. We will continue to monitor events and changes in circumstances surrounding these potential liabilities in determining whether to perform additional actuarial evaluations and whether additional provisions may be necessary. At the present time, however, we do not believe that any additional provisions would be reasonably likely to have a material adverse effect on our liquidity or consolidated financial position. Other Litigation We are currently involved in various other legal claims and legal proceedings (some of which may involve substantial amounts), including claims related to commercial disputes, product liability, employment, and environmental. Although these legal claims and legal proceedings are subject to inherent uncertainties, based on our understanding and evaluation of the relevant facts and circumstances, we believe that the ultimate outcome of these matters will not, either individually or in the aggregate, have a material adverse effect on our business, financial condition or results of operations . We may at any time determine that settling any of these matters is in our best interests, which settlement may include substantial payments. Although we cannot currently predict the specific amount of any liability that may ultimately arise with respect to any of these matters, we will record provisions when the liability is considered probable and reasonably estimable. Significant judgment is required in both the determination of probability and the determination as to whether an exposure can be reasonably estimated. As additional information becomes available, we reassess our potential liability related to these matters. Such revisions of the potential liabilities could have a material adverse effect on our business, financial condition or results of operations.