optimus prime bullet mechanical pencil bullet mechanical pencil diamond robot toy pen children boy learning toy ballpoint pen diy 擎天柱变形笔变形笔金刚机器人玩具笔儿童男孩学习玩具圆珠笔diy

four pens [full set of warlords] with four bullet mechanical pencil [optimus god of war] with a pen core bullet mechanical pencil [blue sea god of war] with a pen core bullet mechanical pencil [red sun warlord] with a pen core bullet mechanical pencil [white spirit of war] with a pen core bullet mechanical pencil [optimus + blue sea]] bullet mechanical pencil [optimus + red sun]] bullet mechanical pencil [optimus + white]] bullet mechanical pencil [red sun + white]] bullet mechanical pencil [optimus + blue sea + white]] bullet mechanical pencil [blue sea + red sun + white]] bullet mechanical pencil [random model] with a pen core

standard with refill [learning is not alone]] 15 pieces [can be written for half a semester]] 30 pieces [can be written for one semester]] 60 pieces [can be written for two semesters]]