If we want to make any thing in the house. It will be a hard work to do it. So Nokia has developed such kind of hard device which can be a replaceable item of hammer and stone. The Nokia lumia 900 have been tested in the same sense. Firstly it was hit my the hammer and was observed that nothing has been happened to the screen. After that the nail was used and it was again hit by the hammer on the nail on different areas of mobile screen. But the screen did not broke up. Finally a nail was crafted to the wood with the mobile working as a hammer and the nail have been passed through the wood. Hence on seeing the video proof it is finally got that Nokia lumia is the toughest mobile device currently in the world.