Features: -With a palm-level size of 4 cm and a feather-level weight of 38 grams.  -FM40 signal remains stable.  -The FM40 has a built-in battery that is charged with a TYPE-C interface, and it has a comprehensive battery life of about 4 hours when fully charged.  -Transmitter of the FM40 is a capacitive directional wireless microphone with a powerful lavalier clip, with a sensitivity of -33DB.  -Receiver of the FM40 comes with 3.5MM headphone monitoring and 3.5MM camera, computer, video camera and other multi-device signal input.     Specifications: Item Name: Lavalier Microphone;  Material: ABS, Metal;  Frequency Range: 566-594;  Wireless Type: UHF;  Directional: Omni-directional;  Sensitivity: -33DB;  Input: 3.5mm TRS for Lavalier Microphone and External Audio Input;  Output: 3.5mmTRS (Camera)+3.5mmTRS (Headphone Monitoring);  Working Distance: 30m to 80m (Open Environment);  Battery Life: TX-3.5 Hours, RX-5 Hours;  Battery Type: Built-in 800mAh Battery (Included);  Charging Port: Type-C;  Charging Voltage: DC-5V ;  Wireless Antenna Gain: 18dbm;  Channel Quantity: 57;  Storage Temperature:-25 Degrees Celsius to 45 Degrees Celsius;  Working Temperature:-10 Degrees Celsius to 45 Degrees Celsius;  Features: Universal, Portable, Wireless, Durable;  Without Back Clip Size: 42.5mm x 45.2mm x 17.2mm/1.67" x 1.78" x 0.68" (Approx.);     Package Includes: 1 x Transmitter;  1 x Receiver;  1 x Storage Pouch;  1 x USB Power Cord;  1 x TRS-TRS Line;  1 x TRS-TRRS Line;  1 x Lavalier Microphone;  1 x Lanyard