Bip39 Checksum. You would probably then do a standard recovery by using a command much like the one particular down below. (This command takes advantage of a sample wallet file bunlded with BTCRecover) What constitutes a "great wallet" is one which has apparent, simple to access documentation on supported BIP https://apollobookmarks.com/story18620040/bip39-generator-https-linktr-ee-bip39-not-known-details-about-bip39-wallets