Supports hands-free calling with a built-in microphone for convenient and secure phone answering. Features CVC noise cancellation and wind noise suppression for clear通话 quality, along with full-duplex call technology. Plays high-quality audio from connected mobile devices. Automatically reconnects after power-on and enters pairing mode automatically. Supports TF card expansion for playing MP3/WAV format music. Includes a car charger with 5V output, compatible with handheld terminal devices. Compatible with TF cards up to 32GB (including 16GB), Class 6 or higher recommended. Specifications: Bluetooth version: V2.1+EDR Audio frequency response: 20 Hz – 20 kHz Microphone sensitivity: 42 dB ± 3 dB Operating voltage: 5 V ± 0.5 V Operating current: 45 mA Standby current: 25 mA Bluetooth operating frequency: 2.402 – 2.480 GHz Effective Bluetooth range: 5 meters RF sensitivity: -92 dBm RF output power: 4 dBm FM transmission frequency: 87.5 MHz – 108.0 MHz FM transmission level: 87 dBµV / 107 dBµV Effective FM range: 2 meters Package Includes: 1 x Car FM Transmitter 1 x User Manual Note: Slight measurement deviations of 0.5–1 inch may occur due to manual measurement. Color appearance may vary slightly depending on monitor settings and lighting conditions.