Husband put it on with no problem. Just follow the directions and you get screen protection for your cell phone. I've used ZAGG on a few of my devices and it really does a great job against scratches.
This ZAGG Shield fit my S21 5G Perfectly.
A plastic alignment guide is included, and makes it SO EASY to install correctly.
I have bought three of these so far because I don't have to fight with it to get them sitting straight on the cell phone.
Highly recommend this one.