Lego Writing Systems Harry Potter pen The Lego writing system is the first of its kind. The only pen you connect and build. Mix and match the colorful beads elements to create fun, new designs every time you write. The Harry Potter pen includes: a create your own pen and bead elements. The pen has a soft grip and uses a replaceable ink cartridge. The grip on the pen is black with flames. The pen has black ink. Just turn the ring to write. The bead elements are olive, burgundy, black, and clear. One bead element is Harry Potter's face. The bead elements are round and square. The bead elements are interchangeable with bead elements from other Lego pens.