The HK Army 13ci 3K Aluminum Tank is a compact High-Pressure Air (HPA) system designed for paintball and airsoft, specifically optimized for magfed markers, pump guns, or HPA-converted airsoft pistols. 
 
 
Key Specifications
Capacity: 13 cubic inches (0.2L).
Pressure Rating: 3000 PSI (200-232 bar).
Regulator Output: Fixed standard high pressure of 800–850 PSI.
Weight: Approximately 458g to 490g (roughly 1 pound) including the regulator.
Dimensions: 255 mm length (with regulator attached) and 50 mm diameter.
Certification: Dual certified (UK Rho / EU Pi) and DOT/TC stamped.
Hydro Testing: Due to its small size, it is generally hydro-test exempt.