OK, going off Topic but I can 'cos it's my threadplease tell me more about Knogs, have never ever heard of them before.
Are they any good, do you chuck them when they die or can you renew the battery?
They look really fun as well as handy.
Clock
Clock
Orange Clockwork - Limited Edition 1998
‘Enjoy your victories of each day'
They're LED lights that use a couple of watch-type batteries. They're not super-bright IMO, but they're good for a "catch your eye" type flasher, and are very easy to attach to just about anything because of the rubbery housing and strap. DH has one on his helmet.
Another "mini-light" that I like is the Blackburn Flea light. Not as easy to mount, but brighter and rechargeable via a standard 1.5v battery.