With firmware versions V1.3.0 (BTC-Only) or later, you can set Electrum 4.0 or later as a watch-only wallet that functions as the companion app for Cobo Vault Essential or Pro.
Tips: If your Cobo Vault is running firmware version 1.1.0/1.2.0/1.2.1, you can set Electrum 3.3.8 as watch-only wallet. As Electrum has released their 4.0 version which has implemented PSBT (BIP 174) as default protocol, so if your Electrum is running version 4.0 or later, please make sure your Cobo Vault has been updated to V1.3.0(BTC-Only) or later.
Setting Electrum as a Watch-Only Wallet
Preparation:
1. Firmware version V1.3.0 (BTC-Only) or later running on Cobo Vault Essential or Pro. (Upgrading Firmware)
2. Electrum wallet 4.0 or later version installed on personal computer or smartphone.
3. MicroSD card (FAT32 format, capacity not exceeding 32 GB).
Pairing Cobo Vault with Electrum Wallet
1. Open Electrum on your personal computer or smartphone.
2. Create a new wallet and select [Next].
3. Select [Standard wallet], then [Next].
4. Select [Use a master key], then [Next].
5. Select the camera icon in Electrum to scan Cobo Vault’s master public key or upload it to Electrum using a microSD card:
1)QR Code Scanning
a. Setup the Cobo Vault and select Electrum as the watch-only wallet. Touch the [•••] button on the top right of the screen.
b. Select [Export Wallet] and get the public key in both QR code and text format.
c. In Electrum, touch the camera icon on the [Create keystore from a master key] page and align the QR code displayed on Cobo Vault with the camera on the device running Electrum to scan.
d. After the master public key has been successfully imported, select [Next].
2)MicroSD Data Transmission
a. Insert your microSD into Cobo Vault and power the device on.
b. Setup the Cobo Vault and select Electrum as the watch-only wallet. Touch the [•••] button on the top right of the screen.
c. Select [Export Wallet] and get the public key in both QR code and text format.
d. Touch [touch here to export the file with micoSD] >[Export] to export the master public key as a .txt file to your microSD card.
e. Take the microSD out of Cobo Vault and insert it into your personal computer or smartphone running Electrum.
f. In Electrum on the [Create keystore from a master key] page, select the folder icon and find the master public key .txt file, select and open it.
g. After your master public key has been successfully imported, select [Next].
6. Set a wallet password.
7. Enter the watch-only wallet.