The Lyle K4 Main Battle Tank
This tank is equipped with a 125mm SUL-20L main gun, primarily firing MK-SEX armor-piercing fin-stabilized discarding sabot rounds, along with a 12mm coaxial machine gun. Powered by a turbine engine, the tank can achieve a maximum speed of 90 km/h.

The turret is fully unmanned, and its internal autoloader mechanism ensures a reload time of 3.5 seconds for the main gun, enabling sustained firepower. Due to its large turret size, the tank has earned the nickname "Big Head Doll."

As part of the first generation formally put into production, the tank is fitted with spaced armor only on the front, while other sections utilize composite armor. The frontal spaced armor of the hull is 600mm thick, with an additional 100mm of composite armor. The turret front features 790mm of spaced armor and 100–50mm of composite armor.

One of the tank's key advantages is its single-person operation. The integrated control system allows the driver to engage targets while on the move. The driver’s station is equipped with two screens: the primary screen for hull operations and a secondary screen dedicated to the main gun.

Although its armor and firepower configurations align with those of a main battle tank, the designers intended it primarily for multi-environment battlefield support roles. This is because, in projected future combat scenarios, the tank’s original 20L main gun—paired with the self-developed MK-SEX armor-piercing round—can only achieve a muzzle velocity of 1,540 m/s, with an actual penetration capability of just 583mm.

The tank comes with almost no additional defensive systems from the factory, lacking even smoke grenade launchers. As a result, its sole means of defense relies on the frontal spaced armor to withstand enemy armor-piercing rounds.