This is a general-purpose 4 Ohm Speaker that can be used for a variety of audio projects. It has a balanced frequency response and is extremely efficient. Excellent high-frequency response. It is a type of transducer that converts electromagnetic energy into sound waves. It converts analog signal inputs from computers or audio players into sound waves. Because of its small size, it can be used in a variety of applications where space is limited. It can be used in Doorbells, Bluetooth speakers, music systems, Alarms and various other projects.