Product Name ACEFAST R2 Wireless Lavalier Microphones Focus Keyword ACEFAST R2 wireless lavalierMicrophones Transmission Distance Up to 15 meters Operating Frequency 2402–2480MHz Transmission Delay About 30ms RF Power ≤4dBm Microphone Battery 60mAh Microphone Working Time Up to 4 hours Charging Case Battery 300mAh Total Working Time Up to 20 hours Charging Input USB-C, 5V⎓0.35A Charging Time Microphone: 1 hour Case Charging Time 1 hour Size 71 × 51 × 26 mm Total Weight 48g