Commitments and Contingencies We lease our offices under operating leases, which expire at various dates through 2022. Our primary operating lease commitments at September 30, 2018 are related to our corporate headquarters in Santa Clara, California. We have additional offices in California, Oregon and New York in the United States and internationally in India, Israel and Berlin. We recognize rent expense on a straight-line basis over the lease period. Where leases contain escalation clauses, rent abatements, or concessions, such as rent holidays and landlord or tenant incentives or allowances, we apply them in the determination of straight-line rent expense over the lease term. Rental expense, net of sublease income, was approximately $0.9 million and $2.2 million during the three and nine months ended September 30, 2018 , respectively, and approximately $0.6 million and $2.0 million during the three and nine months ended September 30, 2017 , respectively. From time to time, third parties may assert patent infringement claims against us in the form of letters, litigation, or other forms of communication. In addition, we may from time to time be subject to other legal proceedings and claims in the ordinary course of business, including claims of alleged infringement of trademarks, copyrights, and other intellectual property rights; employment claims; and general contract or other claims. We may also, from time to time, be subject to various legal or government claims, disputes, or investigations. Such matters may include, but not be limited to, claims, disputes, or investigations related to warranty, refund, breach of contract, employment, intellectual property, government regulation, or compliance or other matters. We are not aware of any other pending legal matters or claims, individually or in the aggregate, that are expected to have a material adverse impact on our consolidated financial position, results of operations, or cash flows. However, our determination of whether a claim will proceed to litigation cannot be made with certainty, nor can the results of litigation be predicted with certainty. Nevertheless, defending any of these actions, regardless of the outcome, may be costly, time consuming, distract management personnel, and have a negative effect on our business. An adverse outcome in any of these actions, including a judgment or settlement, may cause a material adverse effect on our future business, operating results, and/or financial condition.