The Soxai Ring 2, pictured in a matte black finish on the edge of a rock against a dark background. (Image source: Soxai)
Soxai has launched the Ring 2 smart ring in Japan with a slimmer 6.7 mm design, a new Deep Sensing PPG sensor, and up to 14 days of battery life. The ring focuses on sleep tracking and health insights, with no subscription fee.
Japanese startup Soxai has officially launched the Soxai Ring 2. This smart ring joins a growing lineup of scaled-down health-focused wearables from companies like Oura and Samsung. It is being marketed with features like sleep monitoring and long-term health tracking, following a refresh of both its hardware and sensing system over its predecessor.
The Ring 2 is built around a redesigned optical PPG sensor branded “Deep Sensing,” which Soxai says was developed in-house using its own optical and algorithmic know-how. The updated sensor is intended to improve measurement accuracy for heart rate, blood oxygen levels, sleep stages, and indicators linked to sleep apnea risk. Alongside the PPG sensor, the ring also uses an AI-assisted 3D accelerometer and a skin temperature sensor.
Physically, the Soxai Ring 2 is slimmer than the previous model. The ring measures 6.7 mm in width and 2.7 mm in thickness. Weight ranges between 2.1 g and 2.7 g depending on size. The outer shell is made from titanium alloy, while the inner section uses synthetic resin. Soxai offers the ring in five finishes: silver, matte silver, matte black, pink gold, and gold.
(Image source: Soxai)
Battery life is rated at up to 14 days on a single charge, depending on ring size and usage. Charging is handled through contactless NFC wireless charging, with a full charge taking between 60 and 120 minutes. The ring supports Bluetooth Low Energy 5.0 and carries a 100 m water resistance rating.
Data collected by the ring is displayed through a companion smartphone app. It shows sleep scores, sleep duration, and nightly sleep patterns, along with general lifestyle insights. The app also provides tips to improve sleep habits, based on algorithms supervised by experts associated with the Japanese Society of Sleep Research. However, blood pressure measurement is not supported.
The Soxai Ring 2 is priced at ¥39,980 (~$257) in Japan, with no subscription fee required. It is already available for purchase, with buyers able to order a sizing kit or select a known size directly from Soxai’s online store and major Japanese retailers. Please note that Soxai explicitly mentions that the ring won’t ship outside of Japan as of writing.
Buy the Oura Ring 4 on Amazon.
(Image source: Soxai)
(Image source: Soxai)
(Image source: Soxai)
(Image source: Soxai)
Anubhav Sharma – Tech Writer – 1237 articles published on Notebookcheck since 2024
Most of my time goes into writing – and somehow it hasn’t stopped being fun yet.
My work mainly revolves around everyday tech, gaming, watches, DIY modding, and the occasional piece on tech-policy chaos when companies and governments clash. I try to keep things simple and honest, without sounding like a product brochure.
I have a Bachelor’s degree in Computer Science Engineering and an Associate Degree in English Studies from the College of New Caledonia in British Columbia, Canada.
Away from articles and deadlines, life usually shifts to making music, taking photos, or trying to finish games that should have been completed months ago.
Anubhav Sharma, 2025-12-13 (Update: 2025-12-13)
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AloJapan.com