China-based smartphone vendors, including Huawei, Oppo, Gionee and Vivo, are engaging in a race to roll out ultra-thin models, a job which has been played mainly by international brands, according to industry sources.

Oppo launched its ultra-thin model, the Oppo R5, recently, which has a thickness of 4.85mm, breaking the previous record of 5.15mm realized by Gionee on its Elife S5.1, a model released in early 2014.

Meanwhile, Vivo plans to roll out soon its new model, the X5Max L, which will come with a thickness of only 4.75mm, the sources indicated.

However, the ultra-thin designs are not coming at the expense of the performance of the smartphones involved, said the sources, noting that the Oppo R5 comes with a new cooling technology that is able to dissipate heat more efficiently.

Some models released by international brands including Apple, Samsung Electronics and Sony Mobile Communications, in 2014 also came with a thickness below 7mm.

HTC will also join the race in 2015 by rolling out its new flagship model for the year with a thickness of 7mm, revealed the sources.