IO Shield for ASUS PRIME Z270-P motherboard. This model was reconstructed digitally from an image and as such may not be perfect. Imperfections are mostly unnoticeable at scale.
For Z270-A boards try Brusli009's https://www.printables.com/model/823692-asus-z270-az370-a-io-shield
The author remixed this model.
Modifications for PRIME Z270-P