I use these magnets to mount to my base on my GPS to the tank on my motorcycle
I really love the strength of these magnets,took the suction cup off the base of my GPS and uses the magnets in its place.workes great on a steel tank,holds tight even going 80 mph
Pros
This magnet is powerful be careful getting your fingers pintched. Screw access adds ease installation
Cons
Need to be stored carefully to avoid accidental damage