Product review (1 stars): Potentially dangerous to use.
It is potentially dangerous to use with a drill.  I used it for the first time today, and the fiberglass lead wire was flying all over the place.  I can see this poking someone's eyeball out and causing blindness.  Secondly,the roray brush and a 3 foot section of the fiberglass lead came off way up my dryer duct and are stuck somewhere up there, which can cause lint to build up on it and potentially lead to a fire.  AVOID THIS PRODUCT.!!!!!  It may be OK to use without a drill attached as per the directions.