If you are replacing your stock air cleaner on your
Harley-Davidson M8 Touring model (2017-Up), you are going to need this throttle
body support bracket—but only under specific circumstances. Harley-Davidson
offers two different styles of stock air cleaners. This bracket is required
only if your bike does not have the Milwaukee-Eight Power Optimized Air Cleaner
Upgrade from Harley-Davidson, which includes built-in throttle body support.
Here’s an example of the air cleaner style that requires
this support bracket:

Whether you’re customizing your ride with the Zombie Breath
Intake or any other aftermarket air cleaner that lacks a built-in support
backing plate, this bracket is an essential component to ensure your setup is
complete. It provides secure stabilization for your throttle body, maintaining
your bike’s performance and reliability.