Our revenue was $340 million, up 12% overall and 3% on an organic constant currency basis.
Our core organic product revenue increased 9% and driven by growth across our fire service and industrial PPE segments, partially offset by lower fixed gas and flame detection business, which was impacted by supply constraints.
As an example, our backlog has increased $50 million, year-over-year.
Revenue growth was healthy in the third quarter with core revenue growth of 19%.
This included 9% growth in organic core revenue on a constant currency basis.
Adjusted operating margin was 15% in the quarter, which was down year-over-year driven by -- driven primarily by variable compensation resets and higher selling commissions and discretionary costs.
Quarterly revenue of $340 million was up 12% overall and 3% on an organic constant currency basis.
While our noncore business was off considerably on the lower level of APR revenues, it was encouraging to see core product revenues up 19% with 9% organic growth in the quarter.
This has resulted in backlog increasing approximately $50 million year-over-year at the end of the quarter.
Gross profit was 42.9% of sales in the quarter compared to 43.4% of sales in the prior year.
Gross profit margin was negatively impacted by 120 basis points for deal-related costs and amortization.
Excluding this, gross profit margin was up a healthy 70 basis points compared to a year ago.
SG&A expense of $87 million was up $23 million from a year ago on a reported basis.
To level set, Q3 2020 SG&A of $65 million was abnormally low due to favorable compensation-related adjustments and the lack of discretionary spending.
The key drivers of the year-over-year increases are: First, we had an increase of approximately $10 million of expense from the acquisitions of Bacharach in Bristol, of which about $6 million will be recurring going forward; second, variable compensation resets and higher selling commissions added $6 million compared to last year; lastly, Discretionary costs are up $3 million associated with the increase in customer-facing activities.
Our quarterly adjusted operating margin was 15%, down 260 basis points from a year ago.
Looking at our segment performance, the Americas margin was 19.4%, down 160 basis points year-over-year.
International margin was 11.3%, down 290 basis points year-over-year.
Our quarterly effective tax rate was 31.5% on a GAAP basis.
Adjusting for nonrecurring transaction costs and other restructuring matters, the effective tax rate was 24.7% in the quarter.
Quarterly free cash flow was $36 million, well above 100% conversion.
In the quarter, we borrowed a net $282 million of debt to fund our corporate development activity, funded $17 million of dividends to shareholders and invested $11 million in capex.
We finished the quarter with cash of $117 million and net debt of $495 million or 1.8 times adjusted EBITDA.
Bacharach contributed about $15 million of sales in the quarter, in line with what we communicated when we closed the acquisition earlier this quarter.
In the quarter, we had a noncash adjustment to the product liability reserve, which resulted in just about $9 million of additional expense compared to a year ago.
To put it in perspective, we had $11 million lower revenue versus 2019 this quarter.
The backlog is up well over $70 million versus the same period in 2019.
This team recently surpassed a remarkable 10 million hours without a lost time incident.

Summary:
Our revenue was $340 million, up 12% overall and 3% on an organic constant currency basis.
Quarterly revenue of $340 million was up 12% overall and 3% on an organic constant currency basis.