T60 1951-A47 (14.1") - which Ultrabay battery?

[Markstar]

Hi,
I'm a little confused about which battery would be right for this. According to Thinkwiki, the T60 has an Ultrabay Slim and actually, the HDD adapter that I got for this does work.

But, according to this as well as the description of two of the batteries (here and here, it looks like these Ultrabay batteries also work (since it says "T60 - All").

I'm confused - do I need to look for Ultrabay Slim batteries or not?

Thanks in advance!