Make sure you take note of the 3 digit code in the box & keep it in a safe place. Then if you ever decide to loose them again you can order a replacement key from your Alfa Dealer.
At the risk of sounding like an idiot..............David P's advice is good - keep the box and code at home - there are usually 2 keys - only keep one in the car. Sounds obvious I know! But its a load of hassle if you lose the lot. Alfa dealer will have a master set of keys (may not have the older triangular type) that can be used in the event the original keys go missing. Ask yourself if your car really needs locking nuts?
The friendly Alfa Romeo Club - If you are looking to buy or you are already an Alfa Romeo owner, join alfaowner.com today to get the most from your ownership