The 5600 blackmax has a one peice cast aluminium cage and has a thumb bar spool release as Dave has already said ,however it is a far stronger design sits lower on the rod than a 5500c and has a different spool shape ,but the cage is a bit of a let down for our type of fishing i think you might struggle with 4oz and a wet spool as there is very little area to grip the spool due to how wide the casting is on the cage ,it can be rectified but does take a lot of work ,nice strong reel though not a bad choice for light bassing ABU have released some Blackmax reels in the USA that are called Blackmax but look like an ordinary 5000/6000 these are a budget range and do have bushes rather than bearings could possibly be one of these you have seen