how is its switch (means how to turn on and off)??
RYAN K The light is turned on by screwing in the rubber light housing until tight and off by unscrewing until the light goes off.
GARRICK W The light is turned off and on by rotating the head.
DAVID F You turn on or off by simply screwing the light tight. I have been using for several years. Just untighten until light goes off and tighten to turn light on. I have never have a problem with water leakage. Just do not un tighten too much UW. Good reliable light.
EDGAR M just turn the cap on and off
JOHN K The light turns on and off by turning the head of the light. I have carried it in my BCD and not turned it on until I needed it and it did not suffer any ill effects.
Personally, I like the idea of a switch, but design works fine.
HERB H Turns on and off by rotating the bezel. It isn't quite as positive as a switch. You have to rotate the bezel quite a bit to ensure that the light stays off. Too little rotation and the light goes off, but sometimes comes back on,
MARK S The light is switched on and off by rotating the black bezel that holds the lens half a turn
This is a great small pocket dice light I have several
JORDAN F you just turn the top. Impossible to break.
MIKE N Not so good. It's the standard - twist the bezel - style turn on/off these pencil lights use. It flooded within 20 dives. To be fair, I can't say for sure whether or not I overly loosened it, or the o-ring seal failed. But I have another Princeton Tech light with a twist bezel and it's been going great for 5 years. Always perfectly dry inside.
ROBERT B The light has a screw type on and off switch. The lamp head is screwed until contact is made. The off is simply the reverse. I think it is dependable, once off, it stays off. The same for on.