A smart scale is four strain-gauge load cells under tempered glass, a bioelectrical impedance analysis circuit, and a Bluetooth radio. The load cells measure weight to within 50–100 grams. The BIA circuit sends a low, safe current through ITO-coated electrodes on the glass surface to estimate body-fat percentage, muscle mass, water percentage, bone mass, and a dozen other metrics that are, at best, directional rather than clinical. The Bluetooth module sends it all to a companion app on the user’s phone, which is where the brand actually lives.
Zhongshan is the old centre. Camry and its parent Senssun have been making scales there since 1975 — first mechanical, then digital, now connected — and the Zhongshan cluster’s tooling, load-cell, and glass-tempering supply base reflects five decades of specialisation. Shenzhen grafted the smart layer on top: BLE modules, app development, cloud backends, and the startup culture that spawned Yunmai (ex-Xiaomi founders) and Yolanda. The two cities sit 90 kilometres apart and function as one supply chain, with Zhongshan supplying the weighing heritage and Shenzhen supplying the connectivity and software.
The white-label app is the real product. Every ODM in this space offers SDK-level app reskinning so a brand can launch its own-branded iOS and Android app on top of the factory’s algorithm backend and cloud infrastructure. The brand’s customer sees a branded app with branded metrics; the ODM runs the servers, maintains the BIA algorithm, and pushes firmware updates. The hardware is nearly interchangeable across factories. The stickiness is in the app and the data — once a user has six months of body-composition history, switching to a competitor’s app means starting over.
The frontier is medical-grade body composition — segmental BIA with 8-electrode hand-and-foot arrays, FDA-listed devices, and integration with telehealth platforms. Transtek, publicly listed on the Shenzhen Stock Exchange as Lifesense Group (300562), is the ODM bridging consumer and medical, supplying Withings and Beurer alongside its own Lifesense brand while building ECG watches and remote-patient-monitoring systems.