Round Brushes are used to apply lubricant to chains and other moving surfaces.  The whisking action of the bristles evenly distributes the fluid as it reaches the contact surface.  Brushes can also help prevent dirt build up.

This Round Brush has an aluminum holder with a 5/16"-24 female inlet to attach to a mounting shank or directly to a supply line.  The bristles are nylon (stainless steel is also available, see part no. B536-3). 

It can be used as a replacement brush with Round Shank Brush models A2256, A2257, A2260, and Round Valve Brush models A2261, B1008, B1049, and B1009.