No official specs. but my quick measurements here say: 2-1/8 inches wide, 7-3/8 inches tall, including antenna. 5" tall from top of volume knob to bottom of radio, and a 3" antenna. Don’t have weight.
Since these radios use FRS frequencies, there is no provision for an external antenna, as FRS regulations forbid the use of external antennas.
Hope this helps.