Great News for China but what are the 4 subs which are signed please share details and SU 35 is really good fighting plane
https://en.wikipedia.org/wiki/Lada-class_submarine
4 subs, Lada sub ,Russia only made one in 2010, but for AIP problem not mass production, the 4 subs will install with China made AIP system. Two biult in Russia, two built in China. So only 2billion$ for 4 subs, Russia-China co-build sub, also called Amur class, Amur: the boundary river between China-Russia.
20 December 2012, the Russian defense export company signed contract with China about co-designed and built four Amur -1650 fourth-generation conventional submarines for the Chinese navy .
General characteristics
Type: Submarine
Displacement: 2,700 long tons (2,700 t) submerged; 1,765 t Surfaced
Length: 72 m (236 ft 3 in); 67 m on waterline
Beam: 7.1 m (23 ft 4 in)
Draft: 6.5 m (21 ft 4 in)
Propulsion: Electric propulsion motor on permanent magnets
Storage battery with increased service life
2 diesel Air Independent Propulsion (AIP) systems based on oxygen-hydrogen fuel cells
1 shaft
2,700 hp (2,013 kW)
Speed: 21 knots (24 mph; 39 km/h)submerged; 10kt surfaced
Endurance: 45 days
Test depth: 300 m (984 ft)
Complement: 34(38) officers and men
Armament: 6 × 533 mm (21 in) torpedo tubes
18 torpedoes SSM
• RPK-6/SS-N-16 Vodopad/Stallion SUBROC