This 25mm x 14mm speaker is a tough little beast capable of accepting 2W of audio and still producing a clear and accurate sound. The military spec. rating of these speakers means they are dust proof and IPX5 certified water proof. Truly an impressive speaker in a package small enough for most steam installs and the more dedicated diesel installs. Dimensions 0.98" x 0.55" x 0.3" or 25mm x 14mm x 7.5mm Sound Pressure Level 81 dB Â± 3.0 dB at 1W, .5m, 1.5 KHz. Effective Frequency Band 400 Hz. to 20,000 Hz. Power Rating 2W (Typical) 2.5W (Peak) DC Impedance 8 Î© Â± 15 % at 1.0V 900 Hz.