Each number is equal to 0.01ml, a dose of 10 equals 0.1ml

The cartridge holder is inside the pen lid. Screw the pen back together so it's one whole piece, then pull the pen lid off. Watch this short video: Pen assembly video

To easy, flick us a msg and we can check where your package currently is and the ETA

Pen tips screw into the cartridge holder, not the cartridges, Please see F&Q "I'm missing the cartridge holder"

Watch this quick video. This is our favourite way to fill a cartridge, making the whole process Easy and Safe: How to fill a cartridge