The HBSM is a wood sander that is constructed with 4 brushes that are utilized in the brushing out of soft annual rings. These brushes are fabricated either from brass wire or synthetic, and are designed in various hardness and grit based on the wood type utilized. This unit offers two versions; namely, the HBSM 400-4 that is integrated with four drive motors, complete with dimensions of 390 x 180 mm, and the HBSM 500-3 that is equipped with three drive motors. The latter is sized 480 x 180 mm.