【F-999B】Diwenhouse Ultra-High Sensitivity Concrete Microphone Audio 40000x Magnification Sound Collector Listening Device Contents: Main unit x 1 Pin microphone x 1 Needle microphone x 1 AC adapter x 1 Headphones x 1 Special exterior case x 1 【Product Information】 Product Name: Concrete Microphone Model Number: F-999B Color: Silver Body Material: Tin alloy Target Materials: Concrete, wooden walls, mortar, brick, cement, metal, wood, glass, plastic, etc. Current Consumption: 10mA Battery: 3.7V Lithium-ion battery Microphone Sensitivity: -70db Audio Magnification: 40000x FM Frequency: Approximately 100MHz FM Reception Distance: Typically about 50-100m (approximately 150m possible without obstacles) Microphone Input: Stereo Φ2.5mm jack Earphone Output: Stereo Φ3.5mm jack Recording Output: Stereo Φ2.5mm jack Continuous Operating Time (at full power): When connected to a recorder: Approximately 15 hours When not connected to a recorder: Approximately 70 hours Some parts are damaged. It probably can't be used without repair.