New boat...ballast help?

I recently bought a 2009 Supra 21V...It's previously had the ballast upgraded and I'm having trouble identifying the rear locker's FatSac weight/dimensions. The center sac is 800lbs...it says it right on the bag (non-FatSac brand bag).

The rear locker bags are FatSac brand, but I can't seem to locate a serial number on either. Am I just not looking hard enough or do some of their bags not have serial #s (which I believe designate dimensions)

Thanks for any guidance.

Jason