Asus ROG MAXIMUS Z790 HERO LGA 1700 ATX Motherboard - Manual (Page 54)

2-12 Chapter 2: Basic Installation
Chapter 2
E. (optional) Remove the thermal pad of the 2242 M.2 length screw hole and
install the bundled rubber for M.2 backplate if you are installing a single
sided M.2 storage device. DO NOT install the bundled rubber for M.2
backplate when installing a double-sided M.2 storage device.
Follow this step only if you wish to install a single sided M.2 storage device to type 2260.
F. Install your M.2 to the M.2 slot.
G. Rotate the M.2 Q-Latch clockwise to secure the M.2 in place.
Thermal pad Bundled rubber for M.2 backplate