Handmade in Portugal, the All-Season Mule Slipper is outfitted with a tear-resistant nylon upper that breathe through every season The synthetic down used for the insulation is made with a light structure, limiting the chance of your feet overheating when sitting by a backyard fire pit or watching football in your buddy’s new man cave. On the outsole and toe box, a stub-proof barrier is added for confidence in every step. And did we mention the cork-lined insole allows you to wear them with or without socks? Dealer’s choice.