The internal shield and spring key were removed from the design in 2018. 

If your unit still has an internal shield with a spring-loaded key, please contact Whisker Customer Experience. 

They can send you out a new key (with no spring) and a key-hole plug at no cost. Once you remove the internal shield, this will cover the hole in the back of the globe where the shield used to be. 

It is highly recommended to remove the internal shield.

Questions? Visit whiskersupport.com