The tube at left is a General Electric-made 5965 rebranded as "12AT7" by International Components Corporation. Compare it to a typical 12AT7 pictured in the center and a type 5965 tube at the right. The clincher is that the rebrander failed to remove the original tube type, and "5965" can be seen below the rebrand in the second picture.
The 5965 is actually a computer-rated 12AV7. The 5965 has only 2/3 the gain of a 12AT7, and is not suitable for most applications calling for a 12AT7.
Also see our listing of a fake 12AU7, where International Components Corporation rebranded the the same 5965 as a 12AU7.