Description of Property
Enter a brief description of the property you elect to expense (e.g., truck, office furniture, etc.).
Enter the cost of the property. If you acquired the property through a trade-in, do not include any carryover basis of the property traded in. Include only the excess of the cost of the property over the value of the property traded in.
Enter the amount you elect to expense. You do not have to expense the entire cost of the property. You can depreciate the amount you do not expense.
https://www.irs.gov/pub/irs-pdf/i4562.pdf