I purchased these flavorizers after speaking with Weber customer support.  I have a Genesis II E310 grill.  It says both on the box and via customer support that these would work.  They DO NOT.  They are smaller by over 2 inches and smaller in overall size.  I have tried to contact Weber Customer Support 3 times but have been either hung up on or no one is monitoring their support email.  I would not purchase these again.