The AD - 20 is a small, universal, entry-level transducer with a better than entry-level sound. This single-head pickup is only 1" in diameter and 1/4" thick, making it perfect for smaller instruments and a wide variety of applications. It comes with double-sided adhesive film and a jack mounting clip that fits to your strap button making it neat and not intrusive (See pictures. Its frequency range is almost perfectly linear (so it will not colour the acoustic instrument and the output signal is very high for a piezo this size. It is easy to move around various instruments and also to find the sweet spot in your instrument. On the dulcimer shown I have found that I like the sound mounted outside on top as shown whereas on ukuleles I prefer it inside. I have also fitted one of these to a cajon and it sounds absolutely awesome. One of the main advantages of this pick up is that you do not have to drill or cut your instrument as is the case with many other pick up types so it is ideal for high value and treasured instruments Get it fast and free from a respected UK supplier.