The LokSound by ESU Rectangular Speaker with Enclosure is ideal for use in model locomotives as a replacement for a 20 x 40mm speaker. With the help of the built-in passive radiator in conjunction with two rectangular speakers, the module achieves a significantly improved bass response and achieves a considerable sound pressure even at the high and mid-range. The module is particularly suitable for diesel or steam locomotives, where emphasis is placed on contemporary bass reproduction. This speaker includes a built-in enclosure to enhance its output and is rated at 4 Ohms. This rectangular speaker measures 7/8 x 1-21/32 x 5/16′ 22 x 42 x 8mm. Check out the line of ESU speakers to fit your sound projects.WARNING: This product can expose you to chemicals, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov