The American M20 "Super Bazooka" was the pinnacle of design regarding the classic World War 2-era M1 "Bazooka" line. In its original form debuting in late-1942, the portable, shoulder-fired weapon fired a 2.36" rocket projectile capable of defeating armor 3" (76mm) thick at range. The Germans appreciated the type that it designed its "Panzerschreck" tank-killer based on what it saw in captured examples of this American weapon following the Operation Torch Allied landings in North Africa. The M20 followed the M9 which added its own improvements to the line including a new trigger ignition method, two-piece take-down design, and better penetration values.
The new and improved M20 was brought online in late-1944 but did not see a bulk of its combat service until the Korean War (1950-1953).
The M20 was a beefier weapon, its caliber increased to 3.5" (88.9mm) bringing it more in line with the German wartime Panzerschreck weapon which fired an 88mm projectile. The system could now hope to defeat up to 11 inches (280mm) of armor protection which gave it a better showing against the new generation of Soviet tanks taking center stage. Furthermore, range was increased some by 150 meters, giving the weapon a better reach across the battlefield.
With the introduction of the M20A1 in 1952, the weapon now featured a new connector latch assembly and was more or less an improved form of the original M20 production model. The M20B1 was a lighter-weight model as its tubes were completed in cast aluminum. Internally, its system was simplified for the better which both eased production and reduced costs. The M20A1B1 designated was used to mark M20B1 models upgraded with the M20A1 model revisions.