Revenue Recognition We sell our durable systems and disposable units through a direct sales force in the United States and through distribution arrangements in the United States, Canada, Australia, New Zealand, and in portions of Europe, Asia, the Middle East, Latin America and Africa. Components are individually priced and can be purchased separately or together. We receive payment directly from customers who use our products, as well as from distributors, organizations and third-party payors. Our durable system includes a reusable transmitter, a receiver, a power cord and a USB cable. Disposable sensors for use with the durable system are sold separately in packages of four. We provide free of charge software and mobile applications for use with our durable systems and disposable sensors. The initial durable system price is generally not dependent upon the purchase of any amount of disposable sensors. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collectability is reasonably assured. Revenue on product sales is generally recognized upon shipment, which is when title and the risk of loss have been transferred to the customer and there are no other post shipment obligations. With respect to customers who directly pay for products, the products are generally paid for at the time of shipment using a customer s credit card and do not include customer acceptance provisions. We recognize revenue from contracted insurance payors based on the contracted rate. For non-contracted insurance payors, we obtain prior authorization from the payor and recognize revenue based on the estimated collectible amount and historical experience. We also receive a prescription or statement of medical necessity and, for insurance reimbursement customers, an assignment of benefits prior to shipment. We provide a   30 -day money back guarantee  program whereby customers who purchase a durable system and a package of four