I like that it matches my Panavise tray. You can mount the spring and solder roll holder in the same screw hole if you want to play around with it a bit. The problem is that it doesn't fit my soldering iron! I have a standard 45w Craftsman iron and the screws holding the attachment make it too wide to fit in the pen holder. The spring will likely need to be bent. The jaws are not slotted as described. If you want them to make cleaning the soldering tip easier, you'll have to cut them in yourself. The hole in the spring is 11.9mm. My soldering iron is 17mm wide including screws. My wood burner is 9.9mm wide so I can at least see what they are for.