Poolmaster 20193 36" Aluminum Back Brush with Nylon Bristles. Poolmaster’s Commercial Collection offers professional-grade products constructed for the most demanding service use. All commercial products are made of high grade, durable, mar-proof materials that meet professional demands and standards. With 3-feet of cleaning power, Poolmaster’s 36″ Aluminum-back brush is the largest in the collection and covers a lot of pool surface in one brush stroke. The high-quality Nylon bristles are built into a subtle, curve-body design with die-cast Aluminum back and handle and mar-proof end caps for protecting pool surfaces.