Sony ILCA-77M2 - Manual (Page 29)

[10] How to Use Before Use Using the strap
Using the shoulder strap
Attach the shoulder strap to prevent damage caused by dropping the product.
1. Attach both ends of the strap.
[11] How to Use Before Use Attaching the eyepiece cup
Attaching the eyepiece cup
It is recommended that you attach the eyepiece cup when you intend to use the viewfinder.
1. Match the eyepiece cup to the groove on the viewfinder and slide it into place.
To remove the eyepiece cup, grasp it on the left and right sides and lift it up.