This is our basic Magnetic Smartphone holder which works on the majority of the air vents out there. The ones it does not work on are round Audi vents, some of the round Mercedes vents and the round Jeep Vents. These magnetic smartphone holders are very strong and can easily hold the larger iPhone Xs Max smartphones. When installing these smartphone holder clips we recommend you install it on the bottom part of the air vent to allow the bottom of the air vents to use part pf the dashboard for extra support. These work great and are great for basic smartphone holder usage. The magnetic holder consist of 6 strong magnets inside of it.