When you put mechanical pencils and colored pencils together, you get Rainbow Mechanical Colored Pencils. This set of colored mechanical pencils is everything you need for a colorful pencil experience with 12 colors in all. Rainbow Mechanical Pencils aren't your typical mechanical pencils however; they have very thick colored leads; 2mm in fact, so you won't have any problems with lead breakage. Plus, since the leads are so thick they can be sharpened to. See the included pencil sharpener in the set. Running out of colored lead? No problem; Rainbow Mechanical Pencils have refillable colored leads, so when you run out of color you can just simply pop off the top and refill with the included extra lead refill right in the case; also sold separately if you need more.