As I did a little research for my list of hardware wallets in the Croatian local section, I discovered another company that uses Open Source for their wallet firmware:

Skywallet - The firmware has been modified from Trezor
GitHub: https://github.com/SkycoinProject/hardware-wallet

It seems you may be right. I never noticed that before. 
I'll have to update this info on my list too.

@Tibu thank you for posting your suggestion.

I updated the list now and added Satochip with all other Open Source wallets.

---

If I missed any other Open Source hardware wallet, please tell me.

You are correct about Opendime, it is open source and I will ad it to the list, but I would not recommend anyone keeping a lot of bitcoins on Opendime.
Thank you for suggestion.

Prokey wallet is added to the list of Open Source hardware wallets.
Prokey is made in Kuala Lumpur, Malaysia and it's code is based on well known Trezor.

Official website with more information:
https://prokey.io/

HyperMate hardware wallets manufacturer is claiming they are Open Source and you can check that on their Github page but I can't confirm that because I didn't test their wallets myself and it is lacking documentation.
They have two interesting devices offering hardware-level MultiSig support and they claim they are resistant against attacks on program execution, and physical attacks on chips (heated, frozen, filtered...) so it would be good to see someone testing out this claims.
Problem I have with this hardware wallet is that I must use their HyperPay app and can't connect device with other wallets like Electrum, and I can't choose to create my own PIN because it is random generated.


Website: https://hyperpay.tech/hypermatepro/pro
Github: https://github.com/hyperpayorg/hardwallet

Hello,

You can also DIY your own Satochip hardware wallet.
We do sell blank javacard that are compatible with our Satochip Applet.

It's quite easy to make your own hardware wallet :
- Grab a card here : https://satochip.io/product/satochip-diy-and-developer-card/
- Load the code here : https://github.com/Toporin/SatochipApplet/releases

Et voilà

I think what you are looking for can be found on this page. Scroll down to the bottom where they talk about creating your own Satochip hardware wallet. They posted links to the required chips, the files that you need to upload on the chip card, and how to download and configure the various Satochip clients.

dkbit98, thank you for putting this list together. I understand now why open source is imperative for hardware wallets.
In the meantime, I'd like to read more reviews of some of the most popular models from this list, not just the simple listings of technical specs. You might have some resources on the subject in your bookmarks archive. Feel free to share any.

Cobo Vault is shutting down next week.

https://support.cobo.com/hc/en-us/articles/4407973083287-Cobo-Vault-Offline-Notice

Nice to give your users an entire 8 days before shutting down your back end.
Cobo / keystone should still work but no more updates.
But, I would still not use it anymore, you never know what could be lurking somewhere in bad code.

-Dave