CHICAGO, July 1, 2026 /PRNewswire/ — Keystone Capital Management, L.P. (“Keystone”) announced today that funds managed by Keystone have completed the sale of Integra Testing Services (“Integra”, or the “Company”) to funds managed by Harvest Partners, LP (“Harvest”). Integra is a national provider of commercial HVAC testing, adjusting and balancing (“TAB”) services and controlled environment (“CE”) testing and certification to a diverse range of end-markets.

Keystone initially invested in Integra in 2021 after its proactive identification of the industry consolidation opportunity led to the simultaneous sourcing and closing of two original transactions that formed the basis of the platform, Fulton and Associates and Neudorfer Engineers. Since the initial platform creation, Integra has substantially grown revenue, employee headcount and its national footprint through significant organic growth as well as the completion of nearly 20 acquisitions. In partnership with the management team, Keystone played a critical role in building the strategy, foundation and leadership team that enabled Integra to become the market leader in the TAB industry.

“It was truly Keystone’s honor to partner with Dominic Mazzolini, Bill Neudorfer and the other business owners and leaders who joined us in the Integra journey,” commented Jason Van Zant, Managing Director of Keystone. “We will cherish this experience and would like to wish Dominic, the Integra management team, and the Harvest team the very best of luck in this next phase of Integra’s powerful story.”

The Company’s management team, led by CEO Dominic Mazzolini, will continue to lead Integra and remain significant owners of the business. “It has been an unbelievable journey in our partnership with Keystone over the past 5 years,” reflected Mr. Mazzolini. “We shared a vision for Integra to become the national market leader in our industry, which we have achieved. We could not have executed that vision without the steadfast support of Keystone, and we are confident the future with Harvest continues to look bright.”

Terms of the transaction were not disclosed. Harris Williams and Baird served as financial advisors and DLA Piper served as legal advisor to Integra and Keystone Capital. Houlihan Lokey, Solomon Partners, and Jefferies served as financial advisors, and Kirkland & Ellis served as legal advisor to Harvest.

About Integra
Integra Testing Services is one of the nation’s largest independent providers of certified testing, adjusting, and balancing (TAB) and related facility testing services for commercial HVAC systems. With a strong focus on delivering unbiased testing and verification services, Integra helps to ensure optimal conditions for building owners, design professionals, and end users. Integra offers a full suite of services, including cleanroom certification, fume hood testing, pharmacy compliance testing, duct leakage testing, air barrier testing, and commissioning services. Integra’s team of over 600 professionals provides services globally with 30 office locations throughout the U.S., Mexico, and Guam. For more information, please visit www.integratesting.com.

About Keystone Capital
Keystone was founded in 1994 with the objective of investing the personal capital of its partners in high-quality businesses; patiently building long-term value alongside management through organic growth and strategic acquisitions. Keystone currently manages over $1 billion in capital commitments across two funds. To maintain consistency with its historical investment strategy and align interest across all stakeholders, the principals of Keystone collectively represent the largest single investor in both of these funds, which have been structured with an extended life to support Keystone’s belief in investment period flexibility. Over the course of its history, Keystone has completed over 50 platform investments and more than 200 total acquisitions with a focus on commercial & industrial services, food & beverage, industrial technology, professional services, and technical services. For more information, please visit www.keystonecapital.com.

About Harvest Partners
Founded in 1981, Harvest Partners is an established private equity firm with over 40 years of experience investing in middle-market companies and partnering with high-quality management teams to build growing businesses. The firm invests in service-oriented businesses across four core sectors: business services & industrials, commercial services, consumer services and healthcare services. This strategy leverages Harvest Partners’ multi-decade experience in financing organic and acquisition-oriented growth opportunities. The firm has over $20 billion in assets under management as of March 31, 2026. For more information, please visit www.harvestpartners.com.

For Keystone:
Katie Perry
[email protected]

For Harvest:
Jennifer Hurson
[email protected]

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