1) a 650nm 5mw 12X30mm brass case $4.50 from AixiZ ( laser pens won't work!!) 2) a on/off switch from Radio Shack---$1.99 3) a 9-volt clip from Radio Shack---5 for $2.99 4) a 9-volt battery 5) a clip tek gun
connect the red or black wire to the red or black wire of the clip ( one wire only!!). connect the other wire to the switch and the other wire of the clip to the switch. ( for example, i connect the red wire of the laser to the red wire of the clip and the black wire of the laser to one side of the switch and the black wire of the clip to the other side of the switch.
tape or glue the laser on top of gun (or on top of the mouth of the gun) and glue the switch to the side with hot glue and put the battery on to the clip. tape the battery to the side of the gun and you're almost done.