These are the adapters - printed in blue PLA for now, but will eventually be printed in a dark grey ASA type material called ApolloX - that allow the Blend Door and Temperature actuators to be fitted to the box. Both are fitted over existing elements and need glue or screws to hold it in. Screws penetrate the box, but are located specifically to avoid the moving internal parts.
There is also an adapter to fit the EATC Blower Controller into the location where the 4-speed resistor normally goes. THAT job however requires significant cutting of the box.
Lukeyson