TrustedReviews posted a review of the Panasonic ToughBook CF-51

But it's what's beneath the skin that sets the CF-51 apart from many notebook computers. To start with both the base and lid are reinforced with magnesium alloy to protect the screen and internal components. It's this strengthening that allows Panasonic to guarantee that the CF-51 can withstand a drop from a height of 30cm. That might not sound like much, but on the occasion when you drop an expensive piece of kit, you'll notice that it seems to take an eternity before it hits the ground, probably never to work again - quite simply, any kind of shock protection is a good thing.

Panasonic ToughBook CF-51 Review