Table:
|  | Years Ended December 31, |  | Increase (Decrease) |  |
| --- | --- | --- | --- | --- |
|  | 2019 | 2018 | Amount | Percent |
| Cost of revenue: |  |  |  |  |
| Products | $29,816 | $34,066 | $(4,250) | (12)% |
| Services | 19,065 | 17,830 | 1,235 | 7% |
| Total cost of revenue | $48,881 | $51,896 | $(3,015) | (6)% |
Paragraphs:
Cost of Revenue, Gross Profit and Gross Margin
Cost of revenue
Cost of products revenue is primarily comprised of cost of third-party manufacturing services and cost of inventory for the hardware component of our products. Cost of products revenue also includes warehouse personnel costs, shipping costs, inventory write-downs, certain allocated facilities and information technology infrastructure costs, and expenses associated with logistics and quality control.
Cost of services revenue is primarily comprised of personnel costs for our technical support, training and professional service teams. Cost of services revenue also includes the costs of inventory used to provide hardware replacements to end- customers under PCS contracts and certain allocated facilities and information technology infrastructure costs.
A summary of our cost of revenue is as follows (dollars in thousands):
Question:
What is the change in total cost of revenue between 2019 and 2018?
Answer: (48881-51896)/51896 = -5.81