Doubler is a lens that goes in front of the front lens on a scope, they multiply the magnification, but make the scope longer.
Yukon make them for their NVRS line of scopes. Marky610 has modified one to fit the Photon, its actually a 1.7 power, so the Photon ends up as 8.25 power. He's also playing with a larger magnification doubler at the moment. No pricing or availability yet, as he says at the bottom of each of his posts: "Watch this space".
Marky will modify the T20 torch to IR with a new LED & driver. He also makes battery extensions for extended operating life. He has a thread in the sales section.
viewtopic.php?f=9&t=3678
http://www.youtube.com/user/Marky610 is his channel. There is a review of the Photon and a review of the Photon fitted with Doubler & T20.
The T20 operates off an 18650 battery, you will need batteries and a charger.
http://www.torchythebatteryboy.com/ is the recommended source.
Some Bloke modifies Ultrafire 501B torches including new lens and copper heat sinks. He has an add with pic under each of his posts, look at the top of this thread:
viewtopic.php?f=3&t=3719
http://www.youtube.com/user/bolluxthen0?feature=watch is his channel.