4. NET SALES

The following table presents the disaggregation of net sales by revenue recognition model (in thousands):

The timing of revenue recognition, billings, and cash collections results in billed accounts receivables, unbilled receivables (presented as deferred costs on our consolidated balance sheets) and customer advances and deposits (presented as deferred revenue on our consolidated balance sheets), where applicable. Amounts are generally billed as work progresses in accordance with agreed upon milestones. The over-time revenue recognition model consists of NRE and prototype services and typically relates to NRE services related to the evaluation, design or customization of a medical device and is typically recognized over time utilizing an input measure of progress based on costs incurred compared to the estimated total costs upon completion. During the fiscal years ended June 30, 2026 and 2025, we recorded $202,000 and $14,000, respectively, of revenue that had been included in deferred revenue in the prior year. The revenue recognized from the contract liabilities consisted of satisfying our performance obligations during the normal course of business.

The following tables summarize our contract assets and liability balances (in thousands):