Card-Shaped Bluetooth Trackers: 2026’s New Battleground | 钱包里的「隐形守卫」：卡片式蓝牙防丢器为何成为 2026 年新赛道
信用卡大小的卡片式蓝牙防丢器为何在 2026 年走热？本文双语拆解 ROKFORM Signal Card、UWB 取舍、续航对比、托运合规与选购思路。Why are credit-card-sized Bluetooth trackers booming in 2026? A bilingual look at the ROKFORM Signal Card, the UWB tradeoff, battery life, air-travel rules, and buying advice.