Large Oval Speaker is a good plastic frame oval, 8 ohm 1 Watt speaker for HO & larger scales. It measures 1.11 inches wide, 1.57 inches long, and .457" high, or 40mm long, 28mm wide, and 11.6 mm high. It's frequency response is 200 to 20,000 HZ. It's what we used to call our #3 speaker. It fits perfectly in HO engines, or the HO steam engine tenders. It can be canted in an "A" frame manner in narrow body engines, (SD40's etc.), or mounted flat facing up or down. See the 3 view picture for details. As always call to see if you qualify for any additional discounts, and to check the accuracy of your order's weight.