Better to spend a few dollars instead of hundreds if you're looking to build your own lightsaber. This dad shows us all the materials you'll need to do it on your own. All he did was go into a 100 yen shop and bought a couple of items.

He got a transparent manual siphon pump and a mini LED flashlight. Color film and batteries too.

Disassemble the siphon pump because all you need is the suction tube and the cap.

Use wire cutters to remove the bits of the suction tube that you don't need.

Use a box cutter to cut the tapered end of the suction tube. Then close it with the cap.

Once you're done, take colored film and secure it to the flashlight.

And then, secure the flashlight into the handle end of the suction tube.

Done!