This miniature rectangular air-core Wireless Charger coil is a lightweight high-performance Rx coil (receiver coil) exclusively designed for ultra-small Qi wireless charging devices. Made of precision multi-turn high-purity enameled copper wire, the compact square outline fits perfectly into tiny wearables, mini earbud cases, portable beauty gadgets and slim IoT products. The open air-core structure eliminates extra ferrite shielding to reduce overall thickness, supporting stable 5W low-power wireless charging compliant with universal Qi standards.