8.    Intangible Assets

The following provides a breakdown of identifiable intangible assets as of June 30, 2021 and December 31, 2020:

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In connection with the acquisitions of Sports Defense, the Company identified intangible assets of $55 thousand representing technology related and customer related intangibles. These assets are being amortized on a straight-line basis over their weighted average estimated useful life of 4.7 years and amortization expense amounted to $7 thousand for the six months ended June 30, 2021.

As of June 30, 2021, the estimated annual amortization expense for each of the next five fiscal years is as follows:

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