I had the Knog Blinder 4v, it broke in two days of use, I took it back and got another it too broke about a month later, I took it back and said forget it so instead I ended up converting my Cygolite ExpiliOn 350 into a tail light which has worked out great, besides those two large ones I saw on the road mine is the brightest I've seen on the road around where I live but it does have the smaller diameter lens which is far less noticeable then the two larger ones I saw.

Heck, about 90% of all people riding bikes in my city don't even use tail lights at all at night, and another 60% of those have no reflectors either! And the cops don't care, I asked a cop friend of mine why they don't issue tickets and he said because the law says that if they get hit by a car without any lights and or reflectors the cyclists is automatically at fault regardless if the motorist was technically at fault. I think that's weird law, I understand the reasoning but the cops should try to prevent injuries and fatalities by issuing citations to cyclists who don't have lights and or reflectors, and beside the extra money from the fines will go toward needed city funds.