The Achzarit is the best protected infantry carrier in service and can withstand both HEAT and kinetic energy projectiles which would destroy conventional IFVs. The manufacturers claim that the machine can withstand repeated 125mm KE hits over its frontal arc. At 44 tonnes the machine is exceptionally heavy for an infantry carrier. The fact that 14 tonnes of the vehicle's weight is made up of additional, advanced armour, gives some indication as to its high degree of protection.

Whilst armour has been concentrated on its frontal arc, the Achzarit has been carefully designed so that component parts contribute to its overall survivability. Diesel fuel cells to the rear right and left flanks of the passenger compartment act as spaced armour. The rear sides are covered by Toga armoured mesh plates. These have been cut into sections and hinged. This allows the narrow gap between the mesh and the hull shell to be used as storage space for such items as stretchers and water containers.

Multiple efforts have been made to improve crew survival. A Spectronix fire detection and suppression system using Halon gas is fitted. Crew and passengers are provided with individual NBC protection equipment. Two Israeli Military Industries (IMI) CL-3030 instantaneous self-screening smoke grenade launchers, each with six projectiles, are carried. In addition the Achzarit can inject a fuel aerosol into its engine exhausts in order to produce a smoke screen.

The primary target for the Achzarit's armament is enemy infantry. NIMDA originally intended the Achzarit to carry three Rafael OWS. Of a modular design, each was capable of being fitted with either a 7.62mm or 12.7mm machine gun. Alternatively an OWS could be adapted to carry a 40mm grenade launcher. However, budgetary constraints saw just one OWS being adopted as standard, fitted with an FN 7.62mm M240 machine gun. The OWS weighs only 160kg and has a minimal internal footprint. The OWS can be fired remotely, with the gunner completely under armour, or manually with the gunner's head and shoulders out of his hatch. When fired under armour, the gunner uses a periscope with a sight of xl magnification. This allows a 25 degree field of view. A brilliantly illuminated, collimated, red ring comprises the aiming aid. This allows the gunner to traverse and engage a target swiftly and instinctively. An elbow sight, with x8 magnification and ballistic range scale, is fixed to the right of the main sight. Both sights are night capable, with second generation image intensifiers.

The Achzarit also carries up to three other FN 7.62mm machine guns on simple pintle mounts and at least one roof-mounted 60mm mortar which can be used to fire illuminating, smoke and anti-personnel rounds. A total of 10 men are carried, with the driver being seated at the front left with the vehicle commander and 7.62 mm machine gunner to his right. The driver is provided with four day periscopes with an additional six being provided in the rear troop compartment, two on the left side and four on the right.

The machine gunner operates the RAFAEL Overhead Weapon Station which is armed with a 7.62 mm M240 machine gun. There are an additional three 7.62 mm pintle-mounted machine guns, one on the commander's hatch and two over the rear troop compartment. Mounted at either side of the front of the hull is a bank of six IMI CL-3030 instantaneous self-screening system for combat vehicles which were originally installed on Israeli MBTs. This can launch various types of grenade over the frontal arc of the vehicle.

The seven infantrymen are seated to the rear, three on a bench seat on the left side of the compartment, three on individual folding seats on the right and one in the centre of the rear part of the compartment. The driver, commander and machine gunner are each provided with a hatch, with that of the commander capable of being half raised for observation purposes. An additional two hatches are provided to the rear, one over the centre of the crew compartment and the other to its left rear. The infantry can enter and leave the Achzarit via the hatches in the roof or via the hydraulically operated clamshell door located in the rear of the vehicle on the right side. The lower part folds down to form a ramp while the upper part opens upwards.

The original Russian engine and transmission have been removed and a NIMDA-designed power pack has been installed at the vehicle's rear. This unusual power pack is extremely compact and has allowed the installation of the passageway at the rear of the vehicle on the right side which allows the infantry to dismount through the rear clamshell door. This has been achieved without modifying the hull.

Perhaps the Achzarit's main failing is that it is relatively under-powered. For purposes of commonality and logistic support, the Achzarit's power pack is based on that used by the Ml09 self-propelled gun, widely employed by the Israelis. Although NIMDA was more than capable of fitting a more potent engine, funding was unavailable. The initial production model used the Detroit Diesel 8V-71 TTA diesel of 650hp, combined with an Allison XTG-411-4 transmission. This set-up gave the machine a low power-to-weight ratio of 14hp/tonne. Consequently NIMDA introduced the Achzarit 2 with a more powerful 8V-92TA/DDC III engine coupled to the XTG-411-5A transmission. This produces 850hp, giving a power-to-weight ratio of 19.3hp/tonne.

The Achzarit exhibits good cross-country mobility thanks to its modified suspension. This has been upgraded from the T-54/55 original by the Israeli firm Kinetics; it now incorporates modified torsion bars. High-capacity hydraulic bump-stops are now fitted to roadwheels one and five, increasing roadwheel travel from 98mm to 200mm. Perhaps more importantly for the quality of the ride, the new hydraulic bump-stops have increased dissipative energy absorption by a remarkable 750 per cent.

The power pack of the Achzarit Mk 1 consists of the transversely mounted Detroit Diesel 8V-71 TTA water-cooled, two-stroke V-8 diesel developing 650hp coupled to an Allison XTG-411-4 hydrokinetic automatic transmission. The Achzarit Mk 2 power pack consists of a Detroit Diesel 8V-92 TA diesel developing 850hp coupled to an Allison XTG-411-5 automatic transmission. These engines can draw in air from either the crew compartment or the engine compartment through a precleaner with a blower to eject the dust and a paper filter.

While the five roadwheels, drive sprocket and idler of the T-54/T-55 MBT have been retained, the wheels are now sprung by new torsion bars which allow a greater wheel travel, with the first and last wheel stations being fitted with an hydraulic bump stop produced by Israel Aircraft Industries. This suspension upgrade provides the vehicle with better cross-country mobility and allows it to operate with MBTs.

The vehicle has a combat loaded weight of 44 tons compared to the 36 tons of a T-54/T-55 MBT and while the T-55 turret has been removed from the Achzarit, most of the difference in weight between the present Achzarit 44 tons and the 27 tons of the T-55 hull is accounted for by the additional armour protection for improved battlefield survivability.

Standard equipment for the Achzarit includes a fire detection and suppression system, individual NBC system and the vehicle can also lay a smoke screen by injecting diesel fuel into its exhaust outlet on the left side of the hull.

There is known to be a command post variant which lacks the roof-mounted machine guns and is fitted with additional communications equipment for its specialised role.