Review (2/5): These clamps hold alright, but the hex screw is ...
These clamps hold alright, but the hex screw is *not* 1/4 inch, nor is it 6 mm... Of the 20 in the pack, about 4 or 5 can be tightened with my hex driver. The rest slip... And the flat-head screwdriver slot is off center so it's hard to keep the screwdriver in contact. Overall, a pain to deal with. I'm tossing the ones I haven't used.