The MH90 is the part in the centre with the mount attached, onto which the TailCap screws, and on the other end, the Lamp Module screws.
The Lamp Module is made up of a Shock Isolated Bezel, a Lamp Assembly (bulb) and a Lamp Housing.
The MH90 holds two SF123A's.
The Lamp Housing can hold up to two more depending on which Lamp Module you get.
There are four Lamp Modules:
LU60 (6V with P60 Lamp Assembly)
LU10 (9V with MN10 Lamp Assembly) [see photo above]
LU15 (9V TurboHead with MN15 Lamp Assembly)
LU20 (12V TurboHead with MN60 Lamp Assembly)
The Lamp Housings are not available by themselves (only as part of the Lamp Modules or complete WeaponLights) At least that was the position last time I checked.
The best way to turn a Lamp Module into a flashlight is to use an A12 Adapter and an A21 Universal Housing to create a two SF123A black tube instead of the MH90.
I guess that this is not making much sense to most people. I have these parts and photos of them. If you would like to see them, you are welcome to email me:
[email protected]Al