| Accrued expenses and other current liabilities |
Accrued expenses and other current liabilities consist of the following at: | | | | | | | | | | | April 30, 2017 | | July 31, 2016 | Accrued wages and benefits | | $ | 23,300,000 |
| | 23,394,000 |
| Accrued legal costs | | 11,362,000 |
| | 32,469,000 |
| Accrued warranty obligations | | 18,223,000 |
| | 15,362,000 |
| Accrued acquisition-related costs | | — |
| | 2,119,000 |
| Accrued contract costs | | 6,240,000 |
| | 8,348,000 |
| Accrued commissions and royalties | | 3,118,000 |
| | 3,473,000 |
| Other | | 11,601,000 |
| | 12,869,000 |
| Accrued expenses and other current liabilities | | $ | 73,844,000 |
| | 98,034,000 |
|
|
| Product warranty rollforward |
Changes in our product warranty liability during the nine months ended April 30, 2017 and 2016 were as follows: | | | | | | | | | | | Nine months ended April 30, | | | 2017 | | 2016 | Balance at beginning of period | | $ | 15,362,000 |
| | 8,638,000 |
| Provision for warranty obligations | | 4,147,000 |
| | 3,183,000 |
| Adjustment to TCS pre-acquisition contingent liability | | 4,200,000 |
| | 154,000 |
| Charges incurred | | (5,486,000 | ) | | (3,336,000 | ) | Balance at end of period | | $ | 18,223,000 |
| | 8,639,000 |
|
|