The R4M (Rakete, 4 Kilogramm, Minenkopf) is a German air-to-air rocket used by the Luftwaffe during the Second Weltkrieg. Its original warhead is thin-walled much like the HEHC Shells employed by Germany at the time, containing 520g of explosives. The main Luftwaffe fighter to arm itself with these was the Messerschmitt Me 262 and its later variants. While the original design had some serious limitations, once VT (proximity) fuse technology was exported to Germany by Great Britain, the final iterations of the R4M became devastating weapons which could bring down whole Soviet bomber squadrons with a few well-placed volleys, though this variant used a conventional HE-Frag casing with less explosive power. Furthermore, the R4M was later found to have great utility against ground targets when employed en-masse, gaining a similar niche with German forces as the French SNEB Rocket.
Many R4M rockets were fit with HEAT warheads from Panzerfaust rocket launchers, turning them into impromptu anti-tank weapons. In this configuration, they were known as R4HL Panzerblitz II.