two strikes is enough [SEP] this e file works really well except mine only rotates in one direction it has a switch for changing directions but mine only spins clockwise you might not think it is a big deal but it is actually helpful to have the option to switch back and forth i am exchanging it and will update this review once i get the new one which hopefully will work as advertisedthe included bits are decent although only the sanding bands work efficiently on uv gel overlays i bought a separate ceramic carbide bit to use on my uv gels is the correct bit size the included metal bits work fine on natural nailsedit just a day after my last update the replacement drill died it is only been used times and i had it for less than a week the power light comes on but that is it so back it goes and off i go to find a different drill probably for more money but hopefully with more reliability