Full tilt Rubber Sole

Any shop that sells the boots can order them for you or you can find them through Full Tilts website. (http://fulltiltboots.com/ski-boot-parts/soul-parts/hardware). And yes, if they are too worn you do need to replace them for two reasons. First, the shop, normally for liability, has to test the binding after mounting it. If the sole is to worn, the boot normally pre-releases or can cause issues with the toe height of some bindings. Second, if you wear through the replaceable soles and into the plastic of the boot, then the boot is no good anymore. You dont want a gap between a new sole and the plastic if that makes sense. They cost 40 dollars and are 9 screws to replace.

this is my problem, those are the only replacements I can find and they say they only fit the SOUL shell, but the TWALLS are the classic shell...

The classic shell only has a small replaceable heal piece and older TWALLs use this shell. But the last three years (this is including the 2015) uses the Soul shell. This is the same for the Morrison pros. If the boot has a replaceable toe strike, than it is the Soul shell. If its not the soul shell and the toe is too worn to mount than the boot is done unless you can find someone to mount them and dont worry about your health or knees. Try getting something to cover the soles when you walk, something like cat tracks. I know they look stupid and are for gapers but they will save your boots and your wallet.

Twalls should use the Soul shell, if they have three cable buckles and full rubber soles they are the Soul shell

Alright thanks, I didnt realize they used the soul shell now. I bought new heels/toes today.

Good man.