I don't know what the deal is with the on and off. Bought a new cap and was looking for a little switch or tab or somethingb talked with them and they told me then/off was just unscrewing the cap. No switch/tab. COME ON PEOPLE REALLY!
I never use that anyway. This is something I would do if I wanted to save power on my batts for a night or something. I use mine too much to be bothered with turning on/off.