Credit: Core Devices

Nearly a decade after Pebble’s nascent smartwatch empire crumbled, the brand is staging a comeback with new wearables. The Pebble Core Duo 2 and Core Time 2 are a natural evolution of the company’s low-power smartwatch designs, but its next wearable is something different. The Index 01 is a ring, but you probably shouldn’t call it a smart ring. The Index does just one thing—capture voice notes—but the firm says it does that one thing extremely well.

Most of today’s smart rings offer users the ability to track health stats, along with various minor smartphone integrations. With all the sensors and data collection, these devices can cost as much as a smartwatch and require frequent charging. The Index 01 doesn’t do any of that. It contains a Bluetooth radio, a microphone, a hearing aid battery, and a physical button. You press the button, record your note, and that’s it. The company says the Index 01 will run for years on a charge and will cost just $75 during the preorder period. After that, it will go up to $99.

Core Devices, the new home of Pebble, says the Index is designed to be worn on your index finger (get it?), where you can easily mash the device’s button with your thumb. Unlike recording notes with a phone or smartwatch, you don’t need both hands to create voice notes with the Index.

The ring’s lone physical control is tactile, ensuring you’ll know when it’s activated and recording. When you’re done talking, just release the button. If that button is not depressed, the ring won’t record audio for any reason. The company apparently worked to ensure this process is 100 percent reliable—it only does one thing, so it really has to do it well.

The ring is designed to be worn on the index finger so the button can be pressed with your thumb.
Credit: Core Devices

A smart ring usually needs to be recharged every few days, but you will never recharge the Index. The idea is that since you never have to take it off to charge, using the Index 01 “becomes muscle memory.” The integrated battery will power the device for 12–14 total hours of recording. The designers estimate that to be roughly two years of usage if you record 10 to 20 short voice notes per day. And what happens when the battery runs out? You just send the ring back to be recycled.

A different approach to AI

There is a little more to the Index than meets the eye. The ring makes use of generative AI in a way that might have tempted most companies in 2025 to shout about it from the rooftops. However, Pebble isn’t looking to sell you an AI subscription or feed on your personal data.

After you record a voice note, it’s beamed over Bluetooth to your phone (Android or iOS), and it stays there. The recording is converted to text and fed into a large language model (LLM) that runs locally on your device to take actions. The speech-to-text process and LLM operate in the open source Pebble app, and no data from your notes is sent to the Internet. However, there is an optional online backup service for your recordings.

While the company is anxious to talk about the ironclad reliability of voice notes on the Index 01, there’s no such guarantee with an LLM. A model small enough to run on your phone has to focus on specific functionality rather than doing everything like a big cloud-based AI. So the Index will only support a few actions out of the box. Here’s the full list.

• Create or add to notes
• Set reminder
• Create alarm
• Create timer
• Play/pause/skip music track (via button press)

If that’s not enough, you’re in luck. The Index 01 is also designed to be hacking-friendly. The audio and transcribed text is yours to do with as you please. You can route it to a different app via a webhook, and the LLM supports model context protocol (MCP), so you can add new functionality that also runs locally. The AI model will also be released as an open source project.

Credit: Core Devices

The Index 01 comes in polished silver, polished gold, and matte black colorways and US sizes 6 through 13. Preorders start today at the $75 price. Worldwide shipping will begin in March 2026, at which time the price will go up to $99.