Description from Amazon USA : This top performance, wide-range, piezo transducer system is the perfect way to amplify a variety of instruments such as piano, grand piano, harp, dulcimer, double bass, cello, acoustic guitars, mbiras, kalimbas, thumb pianos and many others. Can be mounted on virtually any acoustic instrument and even on your neck to pick up your voice! Includes velcro and putty attachment options allowing you to experiment with the best instrument mounting option for your needs. Jack: Quarter inch, connected mono, with nylon shell and Velcro-type attachment. I ship quickly. Don't forget to check out my other products on amazon such as my Dual piezo contact mic which gives two audio pickup sensors instead of one.