The 9909 stainless steel clamping fork is unique because the cap-head screw is held captive in the slot of the fork so that it can't fall out. Think about how many times and how much time you have spent looking for the exact screw to clamp the forks in your experiment - you will quickly understand the value these forks provide. 9909 clamping fork also has an extra-long 1.5 in. slot providing 50% more positioning range than standard length fork clamps. This extra length also gives 50% more clamping force, owing to this additional leverage.