The handheld cordless straight die grinder 3.6 Li-ion 1300mAh with USB charging is a great tool, not only for grinding crystal resin jewellery. Thanks to its rubber grips, it does not slip out of your hand and it dampens vibrations. You can use it for polishing, milling, grinding, drilling holes and other tasks. Its biggest advantage is that it can be recharged via a USB port, and the special Li-ion battery lasts up to 40 minutes and can be topped up on the go. Thanks to its size, you can also work with it practically anywhere. The shank size is 3.2mm.