It is related to retardation force when dropped. That in turn is related to the height at which the drive is dropped and the elasticity/softness/hardness of the surface.
For example, if you drop the drive from 1 meter of height, less than 350G means the floor material must be soft/elastic enough to stop the fall after about 2.8 mm, or more. In other words, a thick carpet, rubber, foam or elastic plastic. Drop the drive on a hard stone/ceramic non-elastic surface and the retardation force, when it hit, will be way higher than 350G. And the drive is likely to break. A soft wood floor that get a 3 mm dent might perhaps be OK.
It is related to retardation force when dropped. That in turn is related to the height at which the drive is dropped and the elasticity/softness/hardness of the surface.
For example, if you drop the drive from 1 meter of height, less than 350G means the floor material must be soft/elastic enough to stop the fall after about 2.8 mm, or more. In other words, a thick carpet, rubber, foam or elastic plastic. Drop the drive on a hard stone/ceramic non-elastic surface and the retardation force, when it hit, will be way higher than 350G. And the drive is likely to break. A soft wood floor that get a 3 mm dent might perhaps be OK.