Diffuser for Surefire heads?

[foxtrot824]

I am doing a mod on a an E1B head and I would like to ever so slightly diffuse the beam, what material do I use and what glue do I use. I've seen it done on Milky lights and would like the diffused beam with out a big diffuser stuck on the end of the light.
Thanks

 

[The Dane]

Make a piece that fits and place it between the reflector end the front lens:

http://www.leefilters.com/lighting/products/finder/ref:C46DD4ABDDC146/

 

[foxtrot824]

In between the lens sounds like a good idea. Are there any other suppliers in the States?