Pentel Multi 8 http://www.amazon.com/gp/aw/d/B0013NG07U/ref=pd_aw_sim_229_3?ie=UTF8&dpID=51ONWg2KBYL&dpSrc=sims&preST=_AC_UL100_SR100%2C100_&refRID=1AA65D0FSWFRWNN5YX9M