The Dootle Mechanical Pencil's front-loading design requires a little practice initially to get lead replacement down. Lead is stored in the back of the pen, and the stylus can be removed when you need to use the eraser. To refill the device, lead is inserted into the pencil’s tip and easily locks in place, while the pen accepts international standard (capped) rollerball refills. As the stylus tips can wear down after prolonged us, 3 replacement tips are included with every pair of writing utensils.