For a really looooong time. I used to have one, but of course I lent it out and have lost contact with the dork I lent it to.
http://seconds.quechua.com/EN/pdf/prod19.pdf
You can get them in most european countries (hinthint BELGIUM hinthint) but the company that used to sell them in the US is out of business.
Frenzy???? can you help?