BHS has developed a portable screening unit designed to prescreen greenwaste/yardwaste prior to grinding. Removing dirt, rock, sand, and other small abrasive contaminants before grinding greenwaste and wood waste significantly reduces the operational wear and tear of tub grinders and other grinding devices. Feeding the grinder strictly oversized materials also maximizes throughput volume. Resulting benefits include less equipment maintenance and increased production levels. The unit is road legal and self-contained. Screens can also be supplied as stationary or skid-mounted design.