Inventory is recorded at the lower of cost or net realizable value. The cost of substantially all the Company’s inventory is determined by the FIFO cost method. Inventories consisted of the following:

As part of product line exit costs (see Note 1) end of life raw material costs aggregating $621 were written off during the year ended December 31, 2021. During the year ended December 31, 2020 the Company wrote off $68 of raw material and scrap parts primarily due to startup production, model changes and improvements.