This is a long (approx 4x the length of the flashlight) diffuser designed for Olight Baton 3 & 4. It should also be able to fit the Baton 3/4 Pro models too, however I have not tested this as I do not own a Pro model. 

Print out of PLA with a normal support. I do not recommend using the weaker tree type as its a long run up the tube. Print out of white, green, yellow or red, or whatever color you want to try. Kinda looks like a mini Light Saber

***Special Note*** In order to fit the diffuser to the flashlight, you will need to heat form it. Use a lighter or a heat gun to gently heat around the open mouth of the body until it starts to soften. You want to heat about 1/4-3/8" down. Carefully slip the diffuser onto the flashlight and run a little cold water over the PLA to set the form. Doing this will give a solid locking fit of the diffuser to the flashlight.