Easy to Record both sides of the telephone conversation clearly</br>The compact size and in-ear fit allow you to place a phone receiver on your ear normally to record a conversation</br>Best to use with a cell or home phone?? records by placing the receiver on the ear</br>The microphone is covered with silicone rubber to reduce noise when it hits the receiver</br>The mic fits into the ear like an in-ear headphone?? and it includes 3 sizes of Ear Buds: (S x 1?? M x 1?? L x 1) so you can find a snug and comfortable fit. Cord Length 5 foot . No battery required</br></br>Product Description</br></br><b>Directivity:</b> Omni-directional<br><b>Frequency Response:</b> 20 - 20??000Hz<br><b>Plug: </b> Gold-plated??Three-Conductor?? L-shaped mini-plug<br><b>Type of Use:</b> Electret Condenser Microphone<br><b>Cord Length:</b> 5 ft 1.5 m <br><b> Earbuds:</b> 3 sizes (small medium large) <br><b>Plug:</b> 3.5mm mono mini plug<br><b>Battery:</b> No batteries are required</br><br/>http://www.amazon.com/gp/product/B009W4B0W2