push-button phone with smartphone functionality (Gmail, WhatsApp, Google Assistant, Google Maps, YouTube, Facebook) + various applications and games in the KaiStore store
2,4'' QVGA (240*320)
SIM type and quantity
Dual SIM (mini SIM)
GSM 850/900/1800/1900 MHZ
Operating system
Li-Pol, 2000 мА*h (monoblock)
MediaTek MT6572, 2 core, 1.3 Ggz
512 Mb / 4 GB
View all specifications
Where to buy

X-style S3500 sKai – The first Ukrainian smart button

The KaiOS operating system was created as a pleasant alternative to using the basic functions of a smartphone in a classic mobile phone. To improve the user experience, the interface is designed to be modern and intuitive to use. X-style S3500 sKai allows you to access the Internet 3G, Wi-Fi and basic Google programs, including search, maps, assistant and YouTube.

Enjoy all the benefits of a smartphone in your sKai phone.

Download the application on a classic phone? Now it’s easy!

KaiStore offers many interesting things in different categories (games, social networks, lifestyle and more) among which are already installed – Facebook, WhatsApp, Google Maps.

Maximum battery life to maximize your phone’s capabilities.

A battery with a capacity of 2000 mAh will allow you to use the phone for as long as possible for 12 hours in talk mode, or up to 30 days in standby mode.

3G – stay connected everywhere

All settings and files are available at any time. Surf the web, upload and download files, photos and videos. In addition, you can easily configure and share a Wi-Fi access point with devices that are nearby – a laptop, smartphone, tablet, etc.

Trendy design classic

Classic design with trendy curves on the back of the X-style S3500 sKai. The case has a slender shape with rounded edges. The color is chosen from one of the shades of black carbon fiber, and the bright metallic contours give urban chic.

• 2G: GSM 850/900/1800/1900
• 3G: WCDMA 900/2100
2,4'' QVGA (240*320)
Operating system
MediaTek MT6572, 2 ядра, 1.3 ГГц
SIM type and quantity
2 microSIM (Dual Standby)
• оперативна: 512 MB
• вбудована: 4 GB
Memory slot
microSD (для карток об'ємом до 32 GB)
2 Mpx with flash
WiFi, 2.4 GHz,IEEE 802.11 b/g/n. WiFi Hotspot
4.0 (BLE)
+ (built-in antenna).
Can operate without a headset
Phone book
500 contacts;
1 fields per 1 contact;
40 characters in the title
Speed dial
Export & import contactcs
alarm clock, world time, calendar, calculator, torch, e-book reader, Power bank
Audio format support
• MP3
Video format support
• 3GP
• MP4
Wireless Communications:
• Wi-Fi: 802.11 b / g / n
• Wi-Fi access point for the "distribution" of mobile Internet to other devices
• 3G modem (using a USB cable) for "distributing" mobile Internet to other devices

In the basic firmware installed:
• Internet browser
• Facebook
• Google: Search, Assistant, Maps
• Youtube
• WhatsApp
• KaiStore store with a set of games and applications

Multimedia Functions:
• Camera
• Gallery
• Audio player
• Video player
• E-book (installed from KaiStore)
Li-Pol, 2000 mAh (removable)
Working hours:
- talk time - up to 12 hours
- standby time - up to 30 days
Headphone Jack
3,5 мм
Connector for charger
132.8*55.6*14.3 mm
108 g
Body material
In the box
• Mobile phone X-style S3500 sKai with a built-in battery, USB power adapter, USB-cable, wired headset (microUSB), User manual (UA/EN), warranty card
12 months
Sigma mobile reserves the right to change the divice technical specifications and configuration without notice.
Руководство пользователя (на украинском языке)
Руководство пользователя (на английском языке)
Декларация о соответствии (Украина)
Презентация X-style S3500 sKai (на украинском языке)

Sigma mobile company guarantees a high quality and faultless functioning of their devices upon conditions of careful usage and considerations of exploitation rules.

After the expiration of device’s service term, we advise you to contact the Authorized Service Center for preventive maintenance and receiving recommendations for the further exploitation of device. In order to prevent possible misunderstandings, it is preferable to keep the documents that are attached to the device upon its sale (sale receipt or cashier’s receipt, instruction of exploitation, warranty card) during the service term. A warranty card establishes warranty liable for device to the extent, provided by the Law of Ukraine On protection of consumer’s rights.

Warranty conditions

  • A warranty provides free repair or replacement of the device during the warranty term. Warranty service is only provided in the presence of a valid warranty card and fiscal check.
  • The renewal of software is a technical maintenance of the product and is not considered as repair and thereforeis not a valid reason for a replacement or a refund;
  • The Periodic service of device (replacement of batteries, cleaning, etc.) is carried out by request for an additional fee.
  • The warranty term for main devices and accessories is set by Sigma mobile with reference to from the date of device’s sale (look at Table 1).
  • Service term is established by Sigma mobile company in reference to the date of the device’s purchase (look at Table 1).
  • Warranty service is provided exclusively at  Authorized Service Centers in Ukraine. The sheet of service centers may be changed



Warranty terms

Service term

Mobile phones series X-treme Main deviceEighteen months

Three years

Mobile phonesMain deviceTwelve months
TabletsMain deviceTwelve months
Action camerasMain deviceTwelve months
Bluetooth headsetsMain deviceTwelve months
Accessories and batteriesRechargeable batteries (including built-in types)Six months

Two years

Memory cards, cables, headsets and other accessories and parts, which don’t requare to disassemble the mobile device in order to replace.

One month

Table 1

The manufacturer shall not bear warranty obligation regarding the device in the following cases:

  • Violations of rules and conditions of exploitation, adjustment, installation of device, described in the User’s Manual and other documentation, which is transported to the consumer in the complete set with the device;
  • If mechanical damages have occured after the transfer of the device to the consumer;
  • The ingression of inappropriate items, liquids, insects, etc. inside the device during usage;
  • Device’s operation in conditions of excessively high or low temperature, surrounded by high humidity, high dust content;
  • Making schematic-technical, design or software changes, not approved by the manufacturer;
  • Repair or modification of device, performed by unauthorized persons;
  • If the damage is caused by the use of non-standard and/or non-qualified expandable materials, charging devices, spare parts, batteries, electronic media, software products that were not supplied or recommended by the manufacturer;
  • If the damage (defects) is caused by the action of computer viruses or similar programs;
  • If the damage (defects) is caused by non-compliance with standards or technical regulations of the power, cable, telecommunication networks, radio signal power, including features of the relief and other similar external factors, usage of the device on the edge or outside of a network action zone, connection to inappropriate or defective external devices;
  • If the defect occurred due to natural wearing down during the exploitation of the device. In this case, natural wearing down is understood as the consequences of product’s operation, which caused the deterioration of technical status and appearance due to long-term using of this device;
  • If the damage of LCD pixels of screens does not exceed 0.0005 percent of the total quantity of pixels on the screen (according to the ISO 9241-303)
  • The occurrence of force majeure (natural phenomena, fire, lightning, etc.).


The manufacturer shall not carry warranty obligation:

Under no circumstances are the manufacturer or its authorized organizations for unusual, incidental, direct or indirect damage (or losses), including, but not limited to, lost profits, loss or inability to use information or data, expenses of recovering information or data, damages caused by interruptions in commercial, manufacturing or other activity, arising in connection with the usage or inability to use a device.

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