Unfortunately, the two stocks are very similar, and that information is not provided by the manufacturer. Your best option is to contact the manufacturer directly.
The XTS AR Shock Absorbing Stock weighs 0.90 oz. This stock with fit to any mil-spec buffer tube.
The XTS AR Shock Abosrbing Stock adjusts along the buffer tube to adjust length of pull.
Yes, the XTS AR Shock Abosrbing Stock XTS should work fine with that buffer.
The XTS AR Shock Absorbing Stock XTS 104 uses an extended butt pad designed to absorb and reduce recoil impulse as much as possible.
Yes. Both are exactly the same except the 104 has a quick release sling socket on each side and the 106 only has the spots to thread your sling thru. The 104 has those options as well. The pics on both items are actually just pictures of the 106. It took me a second handling both to find the difference and then I forgot which came out of which package before finding the small model number molded into the plastic
Yes, it will. You will want to pair it with a 308 buffer spring and appropriate buffer.