Secure element information updated for ColdCard Mk4 hardware wallet, that now have two secure elements SE1 Microchip ATECC608B and SE2 Maxim DS28C36B, along with STM32 main microcontroller. They are using something called Pairing Secret, that means that secret is shared between three components, two secure elements and microprocessor. If one of those chips get's compromised, wallet with secret will be safe, and they use trick PIN's for improving security of their devices. ColdCard developers explained better in more details how Dual Secure Elements work on their github page: https://raw.githubusercontent.com/Coldcard/firmware/master/docs/mk4-secure-elements.md