Madison-based Sara Investment Real Estate LLC recently purchased a 43,164-square-foot industrial building at 909 Perkins Dr., Mukwonago, from Monster Investments LLC for $1.75 million, or about $40.54 per square foot. The building was previously occupied by Monster Medic. Sara Investment Real Estate plans to lease the building to Gearbox Express LLC, a start-up company that repairs and remanufactures gearboxes for the wind turbine industry. The company will move its offices to the building from Hartland and establish a manufacturing plant there. Dave Hazenfield of The Dickman Company represented Monster Investments in brokering the deal. Jenny Lisak brokered the deal for Sara Investment Real Estate. Mark Gorski of Judson & Associates represented Gearbox Express.