Their canyon asphalt and any fo their models using them have serious issues with knot stoppers. After a month and a half, one of the knot stoppers was gone (they go loose and just fall). When the laces come loose the shoe just spreads wide open and is dangerous to walk on. I have been talking to Tropicfeel support for almost two months. Asked them to send me new laces and replacement knot stoppers since they are easily lost. I even offered to pay for them. They tell you that they will send them but it's a lie. They have told me 4 times "it will arrive next week" but nothing arrives and the shoes cannot be used without their specific laces. Poor lace design and poor support