Both Steel strung and classical acoustic guitars can be fitted with a pickup. Acoustic guitars can have a magnetic pickup which are the same pickup types found on electric guitars. However, the most common pickup on an electro acoustic is called a piezoelectric. The piezo is placed under the bridge inside the guitar. This type of pickup doesn’t work in the same way as magnetic pickups. Rather than use magnets and copper wire the Piezo consists of metal and ceramic parts. Wires are attached to both parts and an electrical signal is created when there are changes in pressure due to the strings being played.