A circular device, 1 inches (3.18 cm) in diameter, with the Regimental motto "Over, Under or Through," lettered around the outer circumference. Diagonal bar running from 10 o'clock to 4 o'clock, with horse's head superimposed thereon and filling the center of the circle. Red keystone between horse's head and 1 o'clock, fishtail cross between horse's head and 1 o'clock. Outer circumference and horse's head in yellow; motto and crossbar in blue; keystone in red; and fishtail cross in black.
The shield is of yellow the Cavalry color; the blue bend is for service as Infantry; the black maltese cross is for the service in Puerto Rico; the red keystone is the Divisional insignia of the Twenty Eighth Division in which elements of the First Cavalry and the Eighth Infantry served.
The distinctive unit insignia was originally approved for the 104th Cavalry, Pennsylvania National Guard on 24 January 1924. It was redesignated for the 104th Cavalry Reconnaissance Squadron (Mechanized) on 8 June 1944. It was redesignated for the 104th Armored Cavalry Regiment on 25 August 1952. The insignia was redesignated for 104th Cavalry Regiment on 9 May 1989. It was amended to correct the previous designation dates and the symbolism on 17 October 2003.