A "magnesium chassis" refers to a frame or structure of a vehicle or device that is made out of a lightweight metal called magnesium. This material is strong, durable, and also helps reduce the overall weight of the object. Full definition
The smartphone sports magnesium chassis with 8.9 mm slim design. (techone3.in)
It, too, isn't greatly changed from its previous versions, with a similar durable and light silver magnesium chassis and conservative look. (digitaltrends.com)
It's in its third iteration without too much changing in its design or appearance, with the same silver - grey magnesium chassis with the unique fulcrum hinge the gap between the display and keyboard that you may or may not dislike. (digitaltrends.com)