Here is the walmart one
http://www.walmart.com/catalog/produ...uct_id=5765569
and here is the bike shop one
http://www.serfas.com/lights/lights_tech.shtml
The walmart one is 18 dollars AND has red flashing led's in the back. The bike shop one is almost 50 dollars and has no led's in the back.
Oh and although I love my LBS im not willing to pay over twice the price unless its a better light.