I have seen a lot of "Backpack Blinkies" that are BARELY VISABLE!

People put them on and think they can be SEEN! WRONG... you have to check to make sure.

You see if the Backpack is empty, there can be a "fold" or flapping going on and the Blinky is in a strange positioning to be SEEN.

I have 3 Blinkies:
Helmet
Seat Post
Rear Rack

I am all about being seen in the DARK. Reflective gear is GREAT also!