Kazam's Tornado 348 is the thinnest smartphone in the world at 5.15mm, but that doesn't leave a lot of room to impress. Also see: Best smartphones 2014/2015.

You might not have heard of Kazam but the firm has produced the thinnest smartphone in the world. 

The Tornado 348 is 5.15 mm although we've measured it at 5.3. Nevertheless, it's the thinnest handset we've ever seen out pacing rivals including the iPhone 6, Sony Xperia Z Ultra and Huawei Ascend P6 

Oppo claims to have an even thinner phone in the R5 but it's not available yet so for now, Kazam holds the title. 

You might think a phone with this title would be expensive but the Tornado is just £249 matching the impressive Honor 6. That's a little more than the reduced price of the still excellent Nexus 5. 

The device looks stylish and has some similarities with the iPhone. Despite being so thin, the structure is rigid but it's so thin that thicker phones are more ergonomic and nicer to hold.  

While glass on the front and rear looks great it makes for a slippery customer and the Tornado is so light at 98g that you'll think it's fallen out of your pocket when it hasn't. See all smartphone buying advice. 

We're impressed by the engineering feat which Kazam has managed here but the phone is let down a fair amount on hardware and performance. 

The screen is a comfortable size at 4.8in but uses a 720p resolution and while an octa-core MediaTek processor sounds good, the device is slower than rivals.  

16GB of internal storage is typical for most smartphones but there's no expandable storage here and the Tornado has basic wireless so lacks NFC and 4G LTE support - the latter being a key omission. 

There are also no extra features such as wireless charging or an IR blaster, which you might not really expect at this price but can be found on the Nexus 5 and Honor 6 respectively.  

Making a phone this thin means less space for components so the Tornado has a pretty small battery and can realistically only last a day unless you use it extremely lightly. 

Things pick up when it comes to photography with a good quality 8Mp rear camera which offers HDR and a 5Mp front-facing camera for selfies. However, the device is outpaced by the Honor 6 with its 13 Mp Sony sensor. 

Software is a plus point for us with a largely stock Android 4.4 KitKat interface - although there are some old-school items like icons. The firm has only really changed the settings menu and notifications bar. Also see: Best Android phones 2014/2015 

Like Samsung, Kazam has opted for off screen buttons which is fine in itself but the old menu button is used instead of the up-to-date recent apps. A long-press is required to access multi-tasking and Google Now which might be difficult for a beginner to figure out. 

If you're looking for the thinnest and lightest smartphone possible then look no further than the Kazam Tornado 348. However, the design of this phone has a negative effect elsewhere and the phone falls down compared to rivals in terms of hardware and performance. The lack of expandable storage and 4G are stand out omissions making the Nexus 5 and Honor 6 better buys. We award four stars.