PU stone is applicable for outdoor wall cladding, with its service life ranging vastly from 3–5 years to 30+ years, determined by material formula and manufacturing craft. Made of polyurethane (PU), qualified outdoor-grade PU stone adopts pure closed-cell rigid PU foam without cheap fillers like calcium carbonate, effectively resisting water hydrolysis, UV rays and temperature changes. Paired with professional silicone mold in-mold painting technology (instead of PVC film lamination), it avoids peeling, bubbling and crumbling, boasting excellent weather resistance and thermal insulation. By contrast, filler-added panels and PVC film-processed products degrade rapidly outdoors. Premium pure-formula PU stone can stably serve outdoor scenarios for 30–50 years, while ordinary versions are only suitable for indoor decoration.