"But the biggest factor is the way in which the device has been put together. Internally, and unusually for a unibody design, the Lumia 920 has a double frame design (full circuit board frame, and separate metal frame), and the screen assembly effectively acts as a third frame. While this internal design architecture, together with a number of related factors around materials tolerance and component positioning, adds extra weight, it also gives the Lumia 920 exceptional mechanical strength and durability, endowing it with a greater ability to endure drops, bumps, and other shocks (and means you're less likely to need a full protective case, with the added size and weight that this entails)."
Awesome!