MR-2 The Portafill MR-2 is an easy to operate, compact, portable and highly reliable screening plant. MS-3 The Portafill MS-3 is a high yield but ultra portable screening plant. MT-5 The MT-5 is the tracked version of the popular wheeled trommel. MR-5 The Portafill MR-5 is designed with heavy duty screening applications in mind.