The Merkava IV is also equipped with the Amcoram LWS-2 laser warning system, with threat warning display installed at the commander's station. This links to the Israel Military Industries POMALS (pedestal-operated multi-ammunition launching system) decoy launcher. One launcher is fitted on either side of the tank, which can launch smoke grenades and decoys.
The Merkava Mk 4 uses a modular ballistic protection and is claimed to provide more effective protection against modern threats involving both protection efficiency and coverage area. The ballistic protection also includes roof protection that provides a capability against overhead attacks. As there is only one roof hatch it is easier to protect the roof with a new passive armour system.
Main armament of the Merkava Mark IVM Windbreaker consists of one 120 mm smoothbore gun, developed by Israel Military Industries (IMI). It can fire various 120 mm munitions, including all standard NATO munitions. It can also fire LAHAT anti-tank guided missiles in the same manner as ordinary projectiles. The LAHAT missile has a range of up to 8,000 m (5.0 mi) when launched from a ground platform, and up to 13,000 m (8.1 mi) when deployed from high elevation. It has effective penetration of up to 800 mm of RHA (Rolled homogeneous) armor steel with its tandem warhead to deal with add-on reactive armor.
Secondary armament consists of a 7.62 mm coaxial machine gun, 7.62 mm machine gun mounted on the right side of the turret roof and an internally mounted 60 mm breech-loaded mortar. The roof-mounted 7.62 mm machine gun can be aimed and fired by the commander from within the turret under complete armour protection and can be traversed through a full 360° . A 12.7mm heavy machine gun is mounted at the front center of the turret and just above the barrel.