They are some microphones, made of plastic sponge and metal materials, durable and safe. they are not easy to produce noise, , suitable for the most kinds of mobile phone brands. suitable for explanation device, loudspeaker, phones, tablets, headset etc. Features - Color: Black - Material: Plastic sponge and metal - Size: Approx. 19x2x2cm Frequency response: 50Hz-20KHz Ω resistance: 2.2 KΩ Microphones size: Ø X6.7 9.7 mm Mental acuity: -32db ±3dB (0dB=1Pa) Square: all/single direction Insert: straight end, elbow Sound channel: mono channel, stereo sound, 4 pole pin - Suitable for interpreter, loudspeaker, mobile phone, tablet, earphone - Sound channel: mono channel, stereo sound, 4 pole pin - They are small, you will carry them easily - , suitable for the most kinds of mobile phone or computer brands - Made of plastic sponge and metal materials, it is durable and safe. Package list: 3 x microphones