Mirrors - size?

[Tdubb]

Mama is buying me mirrors for Valentines day. I need to know/understand fitment. I currently have some aftermarket mirrors that came with the bike. So does my bike need adapters and it already does since it already has a set of aftermarkets? What fitment in general fits my '08 Mastiff? This is what I'm getting.

Biker's Choice Radical Custom Mirrors | 760-751 | J&P Cycles

 

[francoblay1]

There are several Threads talking about it. I did not need any adaptors... I just used the hardware already there from the stock mirrors.

Here an old post from Raywood with a pic.

Here are what the adapter look like. They have 1/2" heads and are 2 1/2" long. You will notice there is one short and one long adapter. I would assume the long one goes on the brake side. I think the adapters purpose is only to increase the shaft size or actually reduce it for aftermarket mirrors.
If the mirrors you want can recieve a bolt vice have a threaded shaft then they will probably work.