Portable screen plants track mounted screens and complete material handling plants with stockpiling conveyors, including rip rap plants for large rock. Wet screen plants are also available to provide washing of materials during the screening process. Inventory available for sale, rent, or lease.Scalper 107T Rock Screen. The Scalper 107T is a patented, extremely heavy-duty, track-mounted screening plant designed to screen heavy rock, sand, soils and . It works best with your 3 to 5 yard (2.5m – 4m) front end loader. View our Scalper 107T Rock Screen.