Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Don't bother with these

These clamps are junk. The screw gets jammed in the clamp threads when you try to adjust the tension. I tried oiling the threads but as soon as there is any resistance from the clamps, the screw ceases up and won't turn. I am glad these weren't the only clamps I had for my girlfriend's Xmas.