Kalashnikov Group, the producer of the famous assault rifles, has a diversified portfolio now with the launch of noiseless reconnaissance drones that can fly continuously for four hours. The company expects Russia's "most advanced" ZALA 421- 16E2 unmanned reconnaissance and surveillance aircraft to undergo state trials later this year, Russia's state-run TASS news agency reported. "There are no analogues of ZALA 421-16E2 systems either in Russia or in the world by their functionality, the simplicity and reliability of operation. Besides, the unmanned aerial vehicle has a noiseless flight mode, which is so important for defence and security agencies," Deputy CEO of ZALA AERO (part of the Kalashnikov Group) Nikita Zakharov was quoted as saying. "The first machines have already been transferred to customers," Zakharov said. The new drone can fly continuously for four hours and can be launched by hand. The drones will be publicly demonstrated at the MAKS international air show outside Moscow in July and at the Army-2017 exhibition in August. Kalashnikov rifles are a hot commodity across the globe. The AK-47 assault was invented by Mikhail Kalashnikov in the former Soviet Union in 1947. Its durability and reliability in combat has made it the most popular assault rifle in the world, rivalling even the AR-15. It is believed that more than 100 million Kalashnikov rifles have been sold worldwide. The inventor of the rifle, Soviet Lt-Gen Kalashnikov, died in 2013.