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100% Open source

BOOM.
Exactly.
How many other solid hardware wallets with OPEN SOURCE you can name? :)

I know of Trezor and Coolwallet

Coolwallet? Open source? Where exactly did you find this info?
AFAIK neither the micro controller nor their firmware is open source.

Quelle: https://www.hardware-wallets.net/coolwallet-review/

Am sure of Trezor, but I only second guess for Coolwallet, but will definitely check the link you shared for more insight

I just learnt about #onekey now, guess this isn't my lucky day 😢

I'm going to stick with open source. Even if you have all the other features, if it is not open sourced; a central party can be trusted and that central point can be take over or influenced by governments and special interests.

Your cryptos, in your hands.