The Urban Combat Division is a small, elite force designed specifically for raids on enemy population centers and industrial zones. It contains few troops in relation to its vehicular power, because any live units it sends in will need to be extracted, usually by spacecraft to another star system.
Most UCD units are air-mobile flyers or jetpack troopers in order to bypass the tight confines of the terrain they fight in. The few ground vehicles are small and expendable, and are usually evacuated and destroyed at the end of a mission because they can't be airlifted out of a hot LZ. Shown below are 4 UCD troopers (including one Sergeant) and one Commander.
UCD troopers carry heavy impact rifles with underslung grenade launchers; commanders carry heavy plasma cannon. Here we see a Commander preparing to ambush a squad of Black Hat Troopers.
The Armored Antipersonnel Vehicle (AAPV) is the standard armored unit of UCD forces, designed to negotiate tight streets and mow down whole squads of infantry with its twin gatling cannons. It's usually used to divert the enemy's attention away from the troops closing on the real objective.
Finally, the P.C.S. S.P.O.T. has been seen already on this forum, but here's a nice 3/4 shot.