Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great for 20 minutes

This product worked wonderfully for the 20 minutes that it worked. I bought several different troy-bilt attachments for my string trimmer, and all of them except the string trimmer itself have failed. This product, like all of the troy-bilt attachments, seems to have a collar swaged onto the drive shaft that is probably intended to prevent damage to the motor head if you hit a rock. The problem is that instead of giving way only under imminent damage, vibration allows it to move and causes the drive shaft to lose contact with the motor head. Permanently. (Or at least until you repair it.) Also, you can't go back and reattach it because it will just move again in a few minutes.