The Protank now shares the same replaceable heads/coils with the new T3/MT3, perhaps saving that maligned device. I personally like the new head/coil on the T3 now. The Evod heads/coils have worked fine for me in the Protank and T3/MT3, though the longer Protank/T3 heads/coils haven't work too well for me with the evod.
Let me straighten you out here just a bit.
eVod heads work on the Protank and Protank heads work on the eVod.
The new T3S heads will work on all 3.
But only the new T3S heads will work on the T3S.
They have a smaller skirt that fits inside the bottom collar of the T3 or T3S tank.
Compare each one and you'll see what I'm talking about.
It's the little metal ring just below the wicks.
HTH