Revenue Recognition As discussed further under Effect of Recently Adopted Amendments to Authoritative Accounting Guidance below, effective January 1, 2018, we recognize revenue in accordance with the guidance in ASC Topic 606 (Revenue from Contracts with Customers). We recognize revenue for the sale of products or services when our performance obligations under the terms of a contract with a customer are satisfied and control of the product or service has been transferred to the customer. Generally this occurs when we ship a product or perform a service. In certain cases, recognition of revenue is deferred until the product is received by the customer or at some other point in the future when we have determined that we have satisfied our performance obligations under the contract. Our contracts with customers may include a combination of products and services, which are generally capable of being distinct and accounted for as separate performance obligations. In addition to the sale of products and services, we also lease certain of our equipment under short-term lease agreements. We recognize revenue from equipment leases on a straight-line basis over the lease term. Revenue is recorded in an amount that reflects the consideration we expect to receive in exchange for those products or services. We do not have any material variable consideration arrangements or any material payment terms with our customers other than standard net 30 or net 60 day payment terms. We generally do not provide a right of return to our customers. Revenue is recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities. Nature of Products and Services We sell thermal management products and semiconductor ATE interface solutions. Our thermal management products include ThermoStreams, ThermoChambers, ThermoChucks and process chillers, which we sell under our Temptronic, Sigma and Thermonics product lines, and Ambrells precision induction heating systems, including EkoHeat and EasyHeat products. Our semiconductor ATE interface solutions include manipulators, docking hardware and electrical interface products. We provide post-warranty service for the equipment we sell. We sell semiconductor ATE interface solutions and certain thermal management products to the ATE market, which provides automated test equipment to the semiconductor market. We also sell our thermal management products to markets outside the semiconductor market which include the automotive, defense/aerospace, industrial, telecommunications and other markets. We lease certain of our equipment under short-term leasing agreements with original lease terms of six months or less. Our lease agreements do not contain purchase options. Types of Contracts with Customers Our contracts with customers are generally structured as individual purchase orders which specify the exact products or services being sold or equipment being leased along with the selling price, service fee or monthly lease amount for each individual item on the purchase order. Payment terms and any other customer-specific acceptance criteria are also specified on the purchase order. We generally do not have any customer-specific acceptance criteria, other than that the product performs within the agreed upon specifications. We test all products manufactured as part of our quality assurance process to determine that they comply with specifications prior to shipment to a customer. Contract Balances We record accounts receivable at the time of invoicing. Accounts receivable, net of the allowance for doubtful accounts, is included in current assets on our balance sheet. To the extent that we do not recognize revenue at the same time as we invoice, we record a liability for deferred revenue. In certain instances, we also receive customer deposits in advance of invoicing and recording of accounts receivable. Deferred revenue and customer deposits are included in current liabilities on our balance sheets. The allowance for doubtful accounts reflects our best estimate of probable losses inherent in the accounts receivable balance. We determine the allowance based on known troubled accounts, if any, historical experience, and other currently available evidence. Costs to Obtain a Contract with a Customer The only costs we incur associated with obtaining contracts with customers are sales commissions that we pay to our internal sales personnel or third -party sales representatives. These costs are calculated based on an established percentage of the selling price of each product or service sold. Commissions are considered earned by our internal sales personnel at the time we recognize revenue for a particular transaction. Commissions are considered earned by third -party sales representatives at the time that revenue is recognized for a particular transaction. We record commission expense in our consolidated statements of operations at the time the commission is earned. Commissions earned but not yet paid are included in current liabilities on our balance sheets. Product Warranties In connection with the sale of our products, we generally provide standard one or two year product warranties which are detailed in our terms and conditions and communicated to our customers. Our standard warranties are not offered for sale separately from our products, therefore there is not a separate performance obligation related to our standard warranties. We record estimated warranty expense for our standard warranties at the time of sale based upon historical claims experience. In very limited cases, we offer customers an option to separately purchase an extended warranty for certain of our products. In the case of extended warranties, we recognize revenue in the amount of the sale price for the extended warranty on a straight-line basis over the extended warranty period. We record costs incurred to provide service under an extended warranty at the time the service is provided. Warranty expense is included in selling expense in our consolidated statements of operations. Refer to Notes 6 and 12 for further information about our revenue from contracts with customers.