Ledger nano s is one of the hardware wallet that commonly used to store digital assets in the form of crypto currency or cold storage of crypto currency. This device is shaped like a USB and This wallet is safer than the usual wallet downloaded online or provided by the crypto exchange. If you are a trader or owner of crypto currency, saving and leaving it on the exchange Will not be the best choice . Because the exchange can be hacked or closed. Ledger Nano S already supports around 1000+ altcoin and BTC. Making it one of the best-performed hardware wallets which is safe and secure to use. What I really like about the security feature is that the wallet Will produce the private key offline through their screen, so basically everything done on the ledger it self. As long as someone didnt have your private key, nothing bad Will happen to your coins. You can store the coins securely up to the third layer of security such as Passphrase, PIN and you can use recovery seed if your hardware is damaged or lost. Ledger nano it self made of sturdy metal with an elegant design. But there have been reports about the deficient security of its devices which makes it possible to infect the devices with malware. In my opinion, user must use official website or purchase the you via "professional resellers" and not from unofficial party to avoid such accident.