Lug Sole Boots are any styling of boot that has a heavy, rubber (or other synthetic) outsole. Lug Sole Boots will typically feature a rugged tread on the outsole.
About Polyurethane:
Polyurethane is the second most common midsole material (EVA is the most common). In comparison to EVA, polyurethane is a heavier, denser material that is more durable and resistant to compression.
