The REON POCKET PRO Plus is a fanless, neck-worn device that uses dual thermo-modules to pull heat away from or push warmth toward the back of the neck. No moving air, which is why it can run quietly enough for an office or a commute, according to Sony Electronics.

In SMART COOL mode, the two thermo-modules alternate in intensity to sustain continuous cooling rather than cycling on and off. SMART WARM mode offers four adjustable heat levels. A companion smartphone app lets users set a target temperature range, with the device adjusting output automatically. On-device buttons handle mode switching without a phone useful for commuters who don't want to pull out a handset every time they step off an air-conditioned train, Sony Electronics notes.

The line originated in 2019 from Sony's internal new business creation program, with commercial sales beginning in 2020. Sony Thermo Technology spun off from Sony Group in 2024 to develop the product independently, according to Sony's corporate blog. The Pro Plus is its newest iteration.

The 20% cooling improvement comes from a 2°C lower plate surface temperature in SMART COOL mode, working alongside an "evolved cooling algorithm," The Verge reported this week. Sony has not broken down how much of the gain comes from the algorithm versus other design changes. Sony calls it the most powerful cooling output in the series' history, per its European press release.

What Sony hasn't clarified: whether "20% higher cooling performance" refers to plate temperature, heat transfer rate, or some other metric measured under controlled lab conditions. A 2°C difference at the plate surface doesn't translate directly into a 2°C sensation on skin, particularly in humidity or through clothing.

One limitation worth noting: coverage of the prior Reon Pocket Pro found that cooling diminished above 35°C ambient temperature, AllThingsGeek observed. That observation applies to the earlier model, not the Pro Plus. Last year, Sony's corporate blog noted that feedback from hotter international markets including countries in the Middle East made the case for a higher-performance model, per that post. Whether the Pro Plus actually closes that gap is unknown; the launch materials don't address performance in those specific conditions.

Sony widened the diameter of the flexible tubing inside the neckband, which the company says increased holding force by approximately 40% over the previous version, according to its European press release. The redesign also reduces micro-movements during walking or light activity, per PR Newswire.

The logic is straightforward. A thermoelectric module transfers heat through direct skin contact. Stable contact is "critical for effective thermal transfer," Sony states. The Adaptive Hold Design suggests Sony sees fit stability as a meaningful limitation worth engineering around.

A new curved cooling surface is designed to better conform to the neck's natural contour rather than resting flat against it, per Sony Electronics. Think of it less as a comfort feature and more as improving the contact patch on a heat sink the spec on paper doesn't reach the person wearing it if the shape doesn't fit. The exhaust vent has also been redesigned with adjustable length and angle, so warm air can be directed away from the body. That matters specifically for high-collar shirts, where heat from earlier versions could recirculate against the neck and undercut the cooling effect, The Verge noted this week.

Sony markets the device to commuters, office workers, and travelers people moving between climate-controlled indoor spaces and hot outdoor environments who need personal temperature control that doesn't draw attention, PR Newswire reported. Rated for up to 15 hours of battery life in SMART COOL mode, it runs fanless and at quiet noise levels, making it viable for meetings and transit, Sony Electronics states. Sony does not publish a runtime figure for maximum cooling mode worth knowing for anyone planning to push it hard, AllThingsGeek noted.

The companion REON POCKET TAG 2 sensor ships with the kit. It measures ambient temperature and humidity, is roughly 18% smaller than its predecessor, and now attaches via carabiner to a bag or belt loop away from body heat, which improves environmental reading accuracy, The Verge reported this week.

One gap worth flagging: Sony's Pro Plus launch materials make no water-resistance claims. Prior coverage of an earlier REON POCKET model noted the device was not waterproof and advised caution around heavy rain or sweat, AllThingsGeek noted. The Pro Plus target use case of office commuting largely sidesteps this, but anyone expecting more versatility should verify durability specifics before buying.

For existing REON POCKET users, the fit upgrade is likely the most relevant change. For first-time buyers, the core question remains open: does any version of this actually feel meaningfully cooler during a hot commute? At €229/£199, that's the bet.

Sony Thermo Technology has been building toward international scale since spinning off in 2024, with the REON POCKET series targeting 22 countries and regions, Sony's corporate blog reported last year. The Pro Plus is the product that needs to perform in European heat and corporate environments not just the temperate Japanese commute where the line first found its audience.

The open questions are the ones that matter most to buyers: how much cooler it actually feels during real commutes rather than controlled conditions, how the fit holds up over months of daily use, and how it performs in the more demanding heat Sony is explicitly trying to address. The neckband change targets what looks like the right bottleneck if prior models lost skin contact during movement, that would have degraded cooling regardless of what the spec sheet claimed. Whether the fix works as well in practice as it does on paper is something only hands-on testing will settle. That testing isn't here yet.