Mossberg 930HS - 4+1 or 5+1?

[Standard]

I'll be getting my Mossberg 930HS in a week or so. I want to get the same magazine extension that the SPX has to get it more or less equal with the barrel length, but I can't find a concrete answer on if it's a 4+1 (and will need a +3 extension) or a 5+1 (and will need a +2 extension). Can anyone confirm?
If you've got a good place to source the Choate extension, I'd appreciate that as well!

[prc77]

get this instead of the Choate. Far better, and CS is great

http://shop.nordiccomp.com/NC-Shotgun-Extension-Complete-Assemblies-for-12ga-12GA-EXT.htm

[Standard]

Thanks, but I can't really afford that. Choate is standard on the SPX, so I'm sure it will do me just fine.

[nrakid88]

By eyeballing it id say plus 3

[FLAWLS1]

I know the standard on my 930 SPX is a +2 from the research that I've done.

[Standard]

I'm back where I started