Replacement cartridges for the 3Doodler are essential to ensure continuous satisfaction with the 3D pen and fun. The set includes 75 additional EKO cartridges, with 25 cartridges in each color: cherry red, plain white, and ocean blue. The 3Doodler Start pen and the special ECO refills have been specifically designed to be completely safe for children. The eco cartridges for the 3Doodler Start are made from safe, non-toxic, BPA-free, and fully biodegradable materials. The plastic that comes out of the 3Doodler Start after melting is warm but not hot. Therefore, once the cartridge is pulled out, children can safely shape it with their hands. The 3Doodler is one of those fantastic ideas that seem so obvious in hindsight that it's hard to believe they have only just been realized. The premise is simple: the 3Doodler Start pen draws with a heated ECO cartridge, allowing 3D objects to be created like a 3D printer, without the need for computer models. The 3Doodler Start pen is extremely easy to use. To start creative play, simply insert the selected color of the ECO cartridge into the device, and after a short while, your child can begin creating. The only limitation is your own imagination. The 3Doodler Start means endless possibilities for long and creative fun for your child.