Boss Kai Nylon/nubuck Lace Runner - White. Material Content: 100% Polyester, 55% Polyurethane 45% Polyester, 65% Polyurethane 35% Polyester, 70% ethylene vinyl acetate 30% Rubber. Washing Instructions: Wipe Clean. Retro-inspired trainers by BOSS, crafted in a combination of materials with textured details, pop-colour elements and branding.