Yeh, there's an LED and light sensitive diode about 1cm in, then there's the very small xenon flash tube about 1/4 the way down the length on the TM and B&T units. I think the Xcortech ones use LEDs, which is a lot smarter.
From looking at mine I'd say it wouldn't actually be hard to flip it around and have it at the other end, but it would take an hour or so and some gluing.
