i remember the first time i used a vibrabeat rug tool, it made so much noise it scared me, i turned the vac off fast as i thought something was wrong with its motor. it had 3 rows of little plastic tubes, about 12 on each row. quite a clatter, a dial on the front was marked vibra or vac. the vac position tightened the rows of beaters so they did not vibrate. neat thing.