Thought I would share my experience with this; it's a royal pain to install properly (especially after installing the oem bumper case). BUT, it adds the grip the phone needs in folded mode for one hand use. I just installed it over the screen protector that comes with the phone.
https://www.olixar.com/huawei-mate-xs-film-screen-protector-2-in-1-pack
https://www.olixar.com/huawei-mate-xs-film-screen-protector-2-in-1-pack
