The colorful Ippo interlocking caps keep your wooden pencils safely in a organized way. It protects your pencil's tip when you carry them in your pencil case or bag. It also prevents your pencils from staining your pencil case. The 4 caps can orignize your pencils by sliding and hooking the tab of one cap into the slot of another cap. The caps can also act as extenders when your pencils become too short. The set includes four packs of Ippo pencil caps that fit most standard wooden pencils.