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What do you do when your phone has no signal?

Deep in the mountains, far from any base station, your phone is useless for keeping your group together. No calls. No messages. No map updates.

Most people accept this as normal. It does not have to be.

Small, affordable radio devices can keep your group connected across several kilometers of mountain terrain. Send messages, share your GPS position, alert others if someone falls behind. They work without a SIM card, without a subscription, and without any internet connection.

At Karida, we sell these devices ready to use in Japan, with everything set up and compliant with Japanese radio regulations.

Who uses this?​

You do not need to be technical. These devices are used by:

  • Hiking groups who want to know where every member is on the trail
  • Hunting teams coordinating across ridges and valleys in silence
  • Outdoor schools and scouts running activities across large areas
  • Event organizers managing staff across a festival or course
  • Rural communities and farmers who need reliable contact in areas with poor coverage
  • Emergency volunteers preparing for when normal communication breaks down

If your group spends time in places where phones stop working, this is worth knowing about.

How does it work?​

Each person carries a small device, roughly the size of a thick credit card. The devices find each other automatically and form a network between themselves. When you send a message or your position updates, it travels from device to device until it reaches everyone in your group.

There is nothing to configure and no account to create. You pair the device with the free app on your phone and you are ready to go.

The more devices in your group, the further messages can travel. A device on a hilltop or ridge can relay messages across a valley that would otherwise be out of reach.

What can you do with it?​

  • See where everyone is on a shared map, updated automatically
  • Send short messages to the whole group or to one person
  • Get notified if someone stops moving or falls behind
  • Monitor simple sensors like temperature or battery level

All messages are encrypted. No one outside your group can read them.

Ready to learn more?​