Jia Cheng Low, a Malaysian team official, cannot help but cherish the soundwave postcard in his hands. Whenever he scans the QR code on the postcard, he can hear the sounds he recorded, bringing back the memories of the 19th Asian Games in Hangzhou.

It is a unique service, offered by the temporary post offices at the Hangzhou Asian Games Village and Main Media Centre.

"Being able to listen to the sound of that exact moment is a profoundly heartwarming experience," he said.

Malaysian esports player Yong Zhan Quan found the postcard to be quite fascinating. "Such memorabilia is exceptionally unique," he said.

According to Qian Weihong, a staff member at the post office, the process of making a customized soundwave postcard is incredibly user-friendly: scan the QR code, record a message or sound for up to 40 seconds, upload a photo and confirm your choices.

Once printed, you'll hold a special postcard in your hands, Qian said.