I found it a bit odd that the instructions state to hold the device with needles pointing downwards in order to avoid the oil back-dripping into the pen. Considering the fact that users would most likely be using this one themselves, the pen would be held at a right angle against the skin, so the manufacturer didn't account for this. I microneedle in front of a mirror so I can see what I'm doing. I don't have the luxury of laying down and having someone else use this device on me just to keep the pen in the instructed position. Needless to say, when I'm done using it, I do have oil the back drifted into the pen. Outside of that 1 issue above, this pen is amazing! UT charges easily, and the battery lasts a long time! The box comes with 3 different needle types, but be aware that the needles are 1-time use only! You will have to invest in the disposable needle kits. The more you consistently use the device, the faster you'll have to purchase needle kits. The device has 5 speeds, so you can adjust it to your sensitivity.