Post-surgery hand rehab device

I recently underwent Scapho-lunate surgery and partial wrist fusion. My hand is left weak with muscle degeneration. My thumb is especially weak and isn’t recovering well since the physio clinic doesn’t have any specific devices to work the thumb.

I want to purchase a hand exercise device to strengthen my hand, but I’m not sure which one is best for overall hand strengthening.

Can you please recommend some of the best devices out there that I can order online?

Thanks in advance.