Rüstsätze were field modification kits produced for the Luftwaffe. They were packaged in kit form, usually direct from the aircraft manufacturer, and allowed for field modifications of various German aircraft used in World War II, predominantly fighter bombers and night fighters. Rüstsätze kits could be fitted in the field, as opposed to Umrüst-Bausätze kits, which were typically fitted in the factory. This was not a hard and fast rule, however; during production runs various Rüstsätze kits were often fitted by factories in order to meet Luftwaffe demands.

/R1
Underfuselage pylon for 500 l (110.0 imp gal; 132.1 US gal) external fuel tank.

/R2
Ratog installation for two Rheinmetall 109-502 solid rocket engines.

/R3
BMW 003R rocket boosted turbojet installation.

/R4
Installation of the FuG 350 Zc Naxos radar warning receiver/detector.

/R5
The standard 4x 30 mm (1.181 in) MK 108 cannon installation.

/R6
Jabo (JagdBomber) equipment, such as bombsights and bomb racks.

/R7
Underwing installation of 12x R4M rockets carried on wooden racks.

/R8
R110BS Air to air rocket installation.

/R9
Ruhrstahl Ru 344 X-4 air-to-air missile installation.

Sources:
Gunston, Bill & Wood, Tony - Hitler's Luftwaffe, 1977, Salamander Books Ltd., London
Wikipedia - ME 262