Asus has announced the Zenwatch 2, the first Android Wear smartwatch to be available in different sizes and with 18 styles to choose from.

To go on sale later this year, the Zenwatch 2 is offered with cases 49mm tall and 45mm tall, echoing the Apple Watch, which measures 42mm and 38mm. Also reminiscent of the Apple Watch is the Zenwatch 2's metal crown, but despite the company promising it offers "a new way to interact" with the watch, it's just an on/off button.

The Zenwatch 2 is available in silver, gunmetal grey and rose gold, and with a range of straps, including a stainless steel band matched to the colour of the case, as well as a number of rubber and leather options. The straps are interchangeable and use standard watch lugs of 22mm and 18mm on the larger and smaller models respectively. In all, there are 18 different models of Zenwatch 2 to choose from. A partnership with Swarovski means one of the leather straps features an embossed diamond pattern and is "tastefully accented with Swarovski crystals."

As for software, it runs Google's Android Wear, which has been tweaked to allow you to create new watch faces in an app called Watch Face Land. Asus' Remote Camera app has been upgraded from last year's Zenwatch to offer complete control over your phone's camera. You can switch between front and rear cameras, zoom in and take photos from the watch's screen.

Other changes include a new magnetic charger with Asus claims to "dramatically improve recharging times," plus a new and slightly curved Gorilla Glass 3 screen cover.

Asus says it is aiming to keep the two sizes priced the same, while differences in price across the range will be determined by the strap you choose. The company says the Zenwatch 2 will be shown off again (along with a full specification list, price and availability) at the IFA technology trade show, which kicks off in Berlin on 4 September.