It has been described as a durable and scratch resistant smartwatch and is a considerable investment, costing from $349 (£299). But the Apple Watch Sport model has been to shown to shatter easily after being dropped from a height of just under four feet (1.2 metres). Apple claims its watch, which has an Ion-X glass display, is 'protected by a lightweight aluminosilicate glass that's especially resistant to scratches and impact.' Scroll down for video . Smash: The Apple Watch Sport edition is shown to shatter easily (pictured) after being dropped from a height of just under four feet (1.2 metres). The model has an Ion-X glass display which is supposed to be 'resistant to scratches and impact' In a video, TechRax drops the 42mm timepiece from a height of four feet (1.2 metres) to simulate what may happen if a wearer drops their watch while tightening or unfastening the strap. When TechRex dropped the watch ‘not aiming at the display,’ in a test conducted in Sacramento, California, it survived unscathed despite a nasty ‘crack’ noise when the timepiece hit the pavement. However, when the watch was dropped so the display hit the floor first, the screen shattered with beads of glass seen on the ground after impact. In the video he exclaims: 'Are you serious Apple? That wasn’t even that bad. That was about three-and-a-half feet!' Deep impact: When online tester TechRex dropped the watch ‘not aiming at the display,’ in a test conducted in Sacramento, California, it survived unscathed despite a nasty ‘crack’ noise when the timepiece hit the pavement. However, when it landed on its face (pictured), it smashed instantly . The watch has 'high performance' rubber straps and the screen is held in an anodised aluminium case, that's 60 per cent stronger than standard aluminium, but is just as light. The Apple Watch Sport (pictured) has high performance' rubber straps and the screen is held in an anodised aluminium case . The tester added: ‘I found it amazing that the amount of shatter that occurred was so tremendous.' When he threw the watch down with force, the screen came off completely. Damage to the screen, such as chips, scratches or indeed shattering,  is not covered by the watch's warranty and is expensive to fix, MacRumours reports. Damage eligible for warranty service includes debris under the screen, a loose back cover and condensation in the heart rate monitor sensor windows. MacRumours also discovered that in the US owners will have to pay repairs fees of $229, $329 and $2,800 for the Sport, Watch and Edition models respectively to fix a cracked or missing crown, missing buttons,or screen damage, for example. It is not known how much these repairs will cost in the UK and other regions and MailOnline has contacted Apple for comment. By comparison, the Apple Watch, which costs from $549 (£479) and Apple Watch Edition from $12,000 (£8,000) have different screens made of Sapphire glass. In a recent test, repair specialists in Cardiff showed that the 38mm Sapphire screen remained scratch-free after being subjected to being rubbed with sandpaper, keyed and even hit with a hammer. Broken: When the tester threw the watch down with force the screen came off completely (pictured). TechRex said: ‘I found it amazing that the amount of shatter that occurred was so tremendous' By comparison, the Apple Watch, which costs from $549 (£479) and Apple Watch Edition from $12,000 (£8,000), have screens made of Sapphire glass. In a recent test conducted by repair specialists in Cardiff, the 38mm Sapphire screen remained scratch-free after being subjected to sandpaper and and hit with a hammer . But some early adopters of the Apple Watch have complained its stainless steel case scratches easily, according to 9to5Mac. The 316L steel used is cold-forged to be 'extra hard', but it seems to scratch in a similar way to the back of an iPod. But it's not all doom and gloom for Apple Watch owners. Another test has shown that the Sport model does live up to Apple's waterproof claims. Unhappy: Some early adopters of the Apple Watch have complained that its stainless steel case (pictured) scratches easily, much like the back of an iPod . Waterproof: But another test has shown that the Apple Watch Sport lives up to Apple's waterproof claims after surviving 15 minutes in a swimming pool (shown above) Apple's CEO, Tim Cook previously said that he showers wearing his Apple Watch and Apple said the Sport edition has an IPX7 water-resistance rating, which means it can be submerged up to 3ft (1 metre) underwater for 30 minutes. And a team at FoneFox in Australia has shown that the watch cannot only withstand a long, soapy shower, as well as being submerged in a bucket of water for five minutes, but can also be left in a swimming pool for around 15 minutes,9to5Mac reported. While the screen couldn't be used while in the pool, because of the capacitive screen technology, when it was fished out afterwards it functioned as normal. The team found that the Crown still worked underwater, allowing them to zoom in and out of apps. The sapphire glass screen in the Apple Watch has remained scratch-free after being subjected to being rubbed with sandpaper, keyed and even hit with a hammer. The test was carried out by Cardiff-based iPhone repairs specialist iPhoneFixed.co.uk, which used a sapphire screen from a 38mm Apple Watch for its experiment. Two out of the three models of Apple Watches have sapphire glass screens - the Apple Watch and Apple Watch Edition. The glass is made from synthetic sapphire, which is created by applying heat and pressure to aluminium oxide powder, before the crystals are processed to remove impurities. The tiny round disks created are ground into shape, and polished, to become glass. Sapphire glass is said to be twice as tough as normal glass and almost as hard as a diamond. To test the durability of the screen, it was rubbed against a stone wall and then with a coin, before being ‘scratched’ by a key. The video capturing the attempts at destruction, shows no scratches were achieved to the screen. It also withstood being rubbed with abrasive sandpaper at some force and hit by a hammer – albeit not very hard. But most impressive, was the screen’s ability to withstand an electric drill being dragged across its surface, without leaving a mark. The test led iPhoneFixed to claim: ‘Sapphire glass is pretty strong and virtually impossible to scratch’.
Apple Watch Sport edition costs $349 (£299) and has an Ion-X glass screen . 'Durable' screen shattered when the watch's face hit the ground first . Screen damage is not covered for free repairs in the Apple Watch warranty . But another test has shown the device lives up to Apple's waterproof claims after it survived 15 minutes in a swimming pool .