One is through magnetic adsorption, installed inrefrigeratorThe cloud outside the door connects to the Puck device. The second is a number of color-changeable electronic tags that can be hung or clipped on food packaging containers.
Nudge Tags – Prevent Food Wastage（via)
When the user puts food in the refrigerator for the first time, he can first rotate the dial on the external Puck device to set the corresponding food to expire in a few days. Then press the Bluetooth pairing button on one of the electronic tags to transfer the data to the corresponding sub-tag.
Every time the refrigerator door is opened, Puck will detect the movement and wirelessly trigger the indicator lights of all sub-tags. Green means it is still in the expiration date, yellow means it should be used as soon as possible, and red means it has expired.
Through the home Wi-Fi network, Puck can also push relevant information to the App on the mobile device.
In addition, the Puck equipped with an LCD touch screen has a built-in lithium polymer battery, which can be used for about 15 days per charge (electronic label), and the replaceable button battery used in the electronic label lasts for up to one year.
Interested friends can move to Kickstarter to support the Nudge Tag crowdsourcing project. If it goes into production smoothly, you can get 1 Puck + 6 electronic tags for US$109, or buy 1 Puck + 12 electronic labels for US$148.