The holds are made of a poly resin so they will last indefinitely outdoors. The screws are another question. I would purchase galvanized or even better stainless steel screws to replace the non-rust proof screws that are included.
Backcountry is awesome! I'm stations in Japan and Backcountry shipped this crash pad to me for free and within a week. That's super fast for an oversized APO AP shipment. Thanks Backcountry I couldn't enjoy this awesome product without you!