Note 7 — Intangible assets, net

Intangible assets, net consisted of the following (in thousands):

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Amortization expense was $937,000, $967,000, and $838,000 for the years ended December 31, 2021 2020 and 2019 respectively. The estimated aggregate amortization expense expected to be recorded in respect of these assets for each of the five years ended 2026 is $771,000, $222,000, $18,000, $1,000 and $1,000, respectively.