HSM 400 Cardboard shredder - Economical and environmentally friendly. Turn your used corrugated cardboard into high quality packing material. The patented bearing plates ensure reliable perforation and padding, and eliminates twisting or bending of the cutting rollers for trouble free, long service life. Cutting rollers are made of hardened steel, the machine is unaffected by small metal parts in the cardboard. The patented form of the grooves in the cutting rollers expands the cardboard into safe and protective padding. The motor is thermally protected against overheating.