Product review (5 stars): A very useful tool
I had bought a cheaper brush.  Actually, it was a stubby brush head on a coiled cable.  But the first time I used it the brush head snapped off inside the dryer vent and I had to pay a repairman $80 to take the vent apart and get it out.

This brush, however, works very well.  It is sturdy and the brush head is securely mounted.  I am very pleased with it.