What brand charger is it?

Walker,

The fuse is there to stop surges getting to your bike when the trickle charger is connected to the mains.  It won't do any harm to your bike or the battery.

BTW: the trickle charger won't work without the fuse being there.

Does every HD come with a Battery Tender port? My Dealer told me they installed it when before I picked up - they said they do it as a courtesy to the customer. Are they taking credit for something HD does stock? The port is on the left side just to the rear of the seat.

I need to know what dealer on which planet does ANYTHING for free? Even when they stand there scratching their nuts they bill you for, at least , the time, possibly a "checked and adjusted various items" turns up on the bill too.

Dealer is Robbos HD in Canberra.

I noticed this port on my Fatboy that was not on my mates Fatboy. He bought his in Sydney. When I asked, the dealer told me it is a Battery Tender port that they install as part of the sale. I think it is because a lot of riders in Canberra don't ride in the winter, so they put the bike to sleep for half the year.

Frasers gave me a charger too.

Smylea hit the nail on the head. most dealers fit them a s a part of the sale,because the alalrms will flatten the battery if stored for any length of time.

Just buy a CTEK charger that comes with a comfort connector that you hook up to the battery via the terminal screws/bolts and hang out the side of the side cover or seat whatever the case may be.
Can be used 365 days a year no probs (do some research - www.ctek.com
Trickle chargers are shit and stuff your battery.
For example if you trickle water into a bottle sooner or later it will over flow, same as current into a battery.
I use one on my bike and my jetski and have 5 years out of both batteries so far with no sign of trouble.