Those are the Supersole 2.0, which is a dual-density PU sole. It will go through hydrolysis and crack if it’s not worn. The resole is, probably without a question, and improvement that looks great!

Coincidentally, I’m wearing the Pecos version of that boot right now (2405). I’ve been a little disappointed in them, to be honest. They don’t fit very well and the sole has worn very, very quickly compared to the 2313 model I wore before these. The heel counter is in terrible shape as well. The downshot is that Wesco, White’s and Nicks all build an Engineer or a harness-style boot and I’m not looking for anything that big, I just want a good leather wellington.