Proton Primus Máquinas e Equipamentos Ltda (Proton Primus Machines & Implements LTDA) is/was located in Mosque, Rio De Janeiro, Brazil, and built construction equipment and 4WD articulated tractors under the Proton Primus brand. The company was founded in 2002. Proton Primus purchased the Brazilian tractor and construction equipment company Müller. They also manufacture construction equipment, such as rollers.