I have found this light on MediaMarkt Istanbul,
It is very small, 3.5cm length and 1.5cm diameter.
it has one 5mm led (above average light output)
You can see it is made of aluminum, is splashproof. has threads and o-ring.
I just tried to access to the led to do a replacement, but it requires very tiny tweezers.
Specs from hama.de site
Light On-Time: 2 h
Model: Flashlight
Number of LEDs: 1
Power of Emission: 6 Lumen
Waterproof: Yes
Diameter: 1,5 cm
Length: 3,5 cm
Weight: 8 g
Battery Type: AG3
Number of Batteries: 4
Colour: Blue
Colour LED: White