The BMP-1 is a fully armored Amphibious Infantry Fighting Vehicle (AIFV). Its low-silhouetted hull has a sharp, sloping front with a conspicuously ridged surface. A centrally located, extremely flat, truncated cone turret mounts a 73-mm smoothbore gun and a 7.62-mm coaxial machine-gun. A launching rail for an AT-3 SAGGER antitank guided missile attaches above the gun. The 290-hp, water-cooled, 6-cylinder diesel engine is in the right front of the hull. The driver's hatch is at the left front, directly in front of the commander's hatch, which mounts an IR searchlight. The gunner's hatch is on the left side of the low turret roof. On the rear of the turret are four large hatches in the roof of the troop compartment; two large exit doors are also in the rear. There are four firing ports in each side of the troop compartment and one in the left rear door. The suspension has six unevenly spaced stamped road wheels, with three track support rollers and a front drive sprocket. A combination of effective antitank firepower, high mobility, and adequate protection makes the BMP a formidable improvement over the earlier BTR-series of armored personnel carriers. It's 73-mm main gun fires a rocket-assisted, fin-stabilized HEAT projectile with an effective range of 800 to 1000 meters. It also has an automatic loader. For longer range antitank capability, the BMP-1 carries the AT-3 SAGGER ATGM, effective to 3000 meters. The BMP is amphibious, propelled through the water by its tracks. It has the range and speed necessary to keep up with the fast-moving tanks it normally follows in offensive formations. The BMP has a three-man crew. This includes the vehicle commander, who becomes the squad leader when the infantry passengers dismount through the rear exit doors. Vision blocks and firing ports in the sides and rear of the troop compartment allow the infantrymen to fire assault rifles (AKM or AK-47) and light machine-guns (PKM or RPK-74) from inside the vehicle on the move. The troops also carry the RPG-7V or RPG-16 antitank grenade launcher, which can be fired by a passenger standing in a rear hatch. BMP IFVs carry the SA-7/14/16/18 and AGS-17 weapon systems in the BMP-equipped MRB's air defense and automatic grenade launcher platoons. When buttoned-up, the crew and passengers have NBC protection in the pressurized and filtered hull. This allows them to operate regardless of the outside environment. The BMP has an infrared searchlight, periscopes, and sights for night operations. It also has a capability to make its own smoke screen by injecting diesel fuel into the exhaust manifold.