East Germany purchased a license for production of the AK-74 in 1981, but that license was for domestic use only. There was an apparent market for export production AKs in the western 5.56mm cartridge, and so the East Germans developed their own new rifle to fill that demand and bring in some much-desired hard currency. That new project would be designated the 940 series of rifles, with fixed-stock 941, folding stock 942 (the subject of this video), compact carbine 943, squad automatic 944, and designated marksman's 945. Development began in 1985 and the first prototypes were ready in 1988. The plan was to make 100,000 rifles the first year and 200,000 per year thereafter, but the fall of the Berlin Wall ended those (very optimistic) plans.

In total, it appears that about 10,000 of the Wieger (named after the town of Weiss, where they were manufactured) rifles were made. These consisted of about 7500 model 941 rifles for India and about 2000 folding-stocked 942 rifles for Peru. The last ones were sold in 1992, and they are quite scarce to find today.

Interestingly, there is a batch of clones in the United States. The InterOrdnance company produced reproduction Wieger furniture, and installed it on a version of the Cugir SAR-3 5.56mm AK rifles made specifically for this purpose. Those are a bit scarce, but can still be found in the US.

Many thanks to the Royal Armouries for allowing me to film and disassemble this rifle! The NFC collection there - perhaps the best military small arms collection in Western Europe - is available by appointment to researchers:
https://royalarmouries.org/research/national-firearms-centre/