Note 7. Property, plant and equipment, net

Property, plant and equipment, net consisted of the following:

As of December 31, 2025 and 2024, the building has been pledged for the purpose of obtaining bank loans.

Depreciation expense for the years ended December 31, 2025, 2024 and 2023 amounted to $236,921, $295,693 and $316,559, respectively.

For the year ended December 31, 2025, the depreciation expense included in the cost of sales, general and administrative expenses, selling expenses, and research and development expenses were approximately $73,343, $153,384, $3,375, and $6,819, respectively.

For the year ended December 31, 2024, the depreciation expense included in the cost of sales, general and administrative expenses, selling expenses, and research and development expenses were approximately $71,780, $215,727, $4,105, and $4,081, respectively.

For the year ended December 31, 2023, the depreciation expense included in the cost of sales, general and administrative expenses, selling expenses, and research and development expenses were approximately $62,917, $246,005, $3,500, and $4,137, respectively.