Sony combines “air conditioning” with “portability” in the new Reon Pocket wearable air conditioner. It’s a small cooling or heating device the size of a credit card wallet. Despite the size, it is designed to keep its user cool regardless how hot the surroundings are, or to keep its user warm during those cold days.

The Reon Pocket is easy to use. Gizmodo reported that users will only need to place it into the pocket of a specially designed shirt, connect it to a specific smartphone app via Bluetooth, turn it on and voila -- instant cooling or heating, depending on the user’s settings.

Sony said the Reon Pocket is capable of lowering a person’s temperature by about 13 degrees Celsius (23 degrees Fahrenheit) during hot days, or raise a person’s body temperature by about 8 degrees Celsius (14 degrees Fahrenheit) on cold days. The company arrived at these numbers after testing the device over “hundreds of simulations.”

Specs

The Reon Pocket is compatible with both Android and iOS, which means it can be used with a lot of smartphones, not just Sony’s own Xperia phones.

SlashGear noted that it uses Peltier, an element used in car and wine coolers. This material consumes a small amount of power, and allows the Reon Pocket to last a full 24 hours with a single 2-hour charge (via USB-C). This simply means users can stay cool (or warm) all day regardless of the temperature around the environment.

Sony said the Reon Pocket can only be used with a specially designed shirt. This won’t be a letdown, though -- the device is so small and light at 85 grams that it stays discreet even when users wear additional clothing on top of the specially designed shirt. And because the Reon Pocket is capable of cooling users down during hot weather, users can wear practically anything they want on top of it.

Crowdfunding

Sony said it plans to release the Reon Pocket in March next year if it gets enough crowdfunding. It will come in two versions: the Reon Pocket Light that only has the basic mode, and Reon Pocket standard that offers three different modes.

Those who want to back the Reon Pocket can go to Sony’s First Flight platform. Prices range from 12,760 yen (about $117) to 19,030 yen (about $175) depending on the version chosen and the number of shirts to go with it. It will only be available in Japan.