Private equity firm the Riverside Co. has acquired Hytec Geratebau GmbH as an add-on deal for current portfolio company Keymile.

Hytec, headquartered in Mannheim, Germany, develops communication networking products designed to withstand harsh environmental conditions. Terms of the deal were not disclosed.

Hanover, Germany-based Keymile manufactures data transmission systems that are used mainly by utility and oil and gas companies. The transaction should expand the company’s product-development capabilities and allow Keymile to enter new markets.

In November, New York and Cleveland-based Riverside acquired Y. International, a Tokyo-based chain of bicycle shops. Also in November, the firm made a majority investment in Arcos, a group of software-as-a-service products that aim to call and assemble crews to restore power and handle work in power plants, as well as fix gas and water leaks.

Riverside also owns a company that provides notifications for severe weather in emergency situations, called Emergency Communications Network LLC, which it used to communicate with employees when Hurricane Sandy hit New York. 

KPMG, Jones Day and Willis advised Riverside on the deal.