Last Updated: September 19, 2025, 08:30 ISTApple introduced its thinnest iPhone ever with the new iPhone Air model that could be part of a whole new series for the company. But Apple is not the first brand to make a thin smartphone, in fact, iPhone Air is not even the thinnest working smartphone to be available in the market. 2 / 5 Oppo R5 launched in 2014 had a sub-5mm thin frame and weight of just 155 grams. The Elife S5.1 stands for its 5.2mm thin design and more importantly, this device weighed under 100 grams with 2,050mAh battery which is some feat. It had an AMOLED display, a 2000mAh battery and a main 8MP rear camera.