This is my third Chek'r screw. My first is probably 20 years old. I have two smaller ones, both SAE and Metric. This expands my ability to sort and organize my metric gear. Since most, if not all, of our two daily drivers are metric, this tool has become a must-have. Like my others, it is well made. You can strip the threads if you try to put the screw in the wrong hole, but the idea is to carefully place the screw in the spot you feel is right. If it connects quickly, you're wrong. Send it back and try the next one. All the popular sizes are here, plus some you'll never see unless you have thousands of clasps like me. The price is reasonable. Highly recommended.