I love this color way of Yeezys, these have been worn quite a bit as a result. Still in good condition and completely wearable with the boost still squishy and comfortable. I don't know whose idea it was to make white insoles, but my use of black socks predominantly has left footprints which I've pictured. The insides are totally clean, it's just something I've noticed happening to Yeezys. I'm sure if you threw them in the wash everything would come out, I just like to leave use of a washing machine up to the new owner, I'm always afraid it will destroy my own pairs!
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