What is the difference between normal and B-Grade? does B-Grade mean open box or what?
http://overclockers.co.uk/showproduct.php?prodid=MB-155-GI
http://overclockers.co.uk/showproduct.php?prodid=BG-156-GI
http://overclockers.co.uk/showproduct.php?prodid=MB-155-GI
http://overclockers.co.uk/showproduct.php?prodid=BG-156-GI