They go into the black battery holder(you wouldn't need the thing the batteries go into). Here is the one I have.[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXMGW5&P=ML]this[/link] You might want to hurry they sell out quickly and are almost gone. They work a LOT better than alkaline batteries. Night and day difference.