Wolo MM II 12 Volt Compact Motor Driven Siren Its length is 4-1/2 inch x width is 2-5/8 inch x height is 3-1/8 inch Compact in size but produces a powerful sound Siren has been engineered to be perfectly balance virtually eliminating all vibration Made to look great in any engine compartment Easy to install with two wires and can be used in any 12 volt vehicle