This flashlight holds up to three LEDs, and for a projection there should only be one for a clear image. For a projection, I just made a cover with an Aperture Science logo-shaped hole, and the hole that goes over the cylinder on the flashlight to keep it on has a friction fit with a diameter of just over 4 mm. Inside the flashlight, I have a switch with 2 CR2032 batteries to power the LEDs.