The MyMobileWatch M500 works on GSM Triband frequencies which are 900Mhz, 1800Mhz and 1900Mhz.

With a much smaller set of the features posted on the company website, the MyMobileWatch M500 is not water resistant, support Triband GSM network and has a 400 mAh rechargeable battery. Sim card slot is designed at the back of the phone under the battery. The battery is fixed on the back cover. The M500 has a single LCD display which consists of three main areas:

• The First line displays status icons, which indicate signal strength, remaining power of the battery, etc.
• The Middle lines display text and graphics, including numbers, text and animated icons and also the information you enter.
• The Last line displays the functions currently assigned to the two left
  and right soft keys.

It is not sure how it done the sms input. Image viewer and video player are available although it is somehow useless on the small screen. The music player will be able to play mp3 music files. According to the specification you can have up to 120 minutes talk time and 100 hours standby time; an incredible performance if it can achieve that.

Specifications:

• Network (in Mhz) GSM 900/1800/1900
• Dimension (in mm) 53.9 mm × 44 mm × 16.3 mm
• Weight (in grams) Appr 55
• Battery Li-ion 400 mAh
• Standby Time * Upto 100 Hours
• Talk Time * Upto 120 Mins
• Charging Time Around 2 Hours
• First Time Charging 4~6 Hours

Source