A rotary brush configured to isolate vibration during use reducing vibration at a hand-held power tool to which the brush is coupled. The brush has wires arrangeable in tufts extending from a hub sandwiched between two plates assembled to a tool coupling having an isolator therebetween. The isolator and coupling are part of a vibration-isolating assembly having a radial isolator carried by a coupling shaft located between the (i) shaft, and (ii) hub and plates preventing brush vibration from being transmitted to the tool through a coupling end of the shaft mounting the brush to the tool. The isolating assembly preferably includes an axial isolator between (i) each flange and (ii) the hubs and plates. Isolators are made of vibration dampening material and can be formed into a single isolator of one-piece unitary construction. A preferred brush is a cup brush having plates contoured to define wire supporting cups.