Basically a Railgun Type 210 mounted on a HEMTT

Specifications (HEMTT)
Weight   42,500 lb (19,278 kg) unladen; 69,000 lb (31,298 kg) laden (a-kit); 75,500 lb (34,246 kg) laden (b-kit); 109,000 lb (49,441 kg) (GCWR)
Length   409 in (10.39 m)
Width   96 in (2.44 m)
Height   118 in (3.02 m) (over spare tire)
Crew   2
Armor   a-kit/b-kit; U.S. Army Long Term Armor Strategy (LTAS) compliant
Engine   Caterpillar (CAT) C15, 15.2-liter, 6-cylinder inline water-cooled EPA 2004 compliant diesel
515 hp (384 kW)
Payload capacity   rated at 10 tons
Transmission   Allison 4500SP 5-speed automatic with Oshkosh enhanced 55,000 2 speed transfer case
Suspension   Holland ADS-240 air (front); Holland AD-246 air (rear)
Fuel capacity   155 US gal (587 l)
Operational
range
300 mi (483 km) loaded
Speed   62 mph (100 km/h)
Steering
system
power-assisted on front tandem

Specifications (Railgun Type 210)
Weight   22 metric tons
Barrel length   55 calibres
Crew   : entirely automatic
Calibre   100 mm
Elevation   29°/s
Traverse   40°/s
Rate of fire   90 rounds per minute
Muzzle velocity   870 m/s
Effective firing range   
17,000 m (elevation 40°)
Maximum practical range:

6,000 km against aerial targets
12,000 km against surface targets

fires laser- and infrared-guided shells
mounted in a reduced radar cross-section turret.