addition, the bulge housing unknown sensors on board Type 039B in the forward section of the top edge of the conning tower is absent on the new boat launched in April 2014, but there are three white lines at the top of edge of the conning tower on both sides, presumably for environmental sensors. This new boat is claimed to be an upgraded variant of Type 039B. Type 039C: Variant with redesigned stealth sail. First spotted in May 2021 in Wuhan. Export variant: S20 At IDEX-2013, China revealed a scaled-down version of Type 039A submarine designated as S20, specially intended for export. The main difference between S20 and Type 039A is that the AIP system on the original Type 039A is deleted, but can be available and easily integrated due to modular design of S20, if potential customers choose to purchase AIP systems separately. Due to its modular design, a variety of sensors and weapons can also be easily adopted up on customers' requests. Specifications of S20: Structure: double hulled Length: 66 meter Beam: 8 meter Draft: 8.2 meter Surface displacement: 1,850 tons Submerged displacement: 2,300 tons Maximum speed: 18 knots Cruise speed: 16 knots Range: 8000 nautical miles at 16 knots Endurance: 60 days Crew: 38 total Maximum depth: 300 meters Export :- On 2 July 2015, the Royal Thai Navy (RTN) formally selected China's Yuan-class (Type 041) platform to meet a requirement for three submarines. The RTN's procurement committee voted unanimously in favour of purchasing the submarine, which has been designated S26T (Thailand), a modified export version of the Yuan class. On 1 July 2016, the RTN submitted a funding plan for its 36 billion baht submarine procurement project to the cabinet for consideration with the expenditure to be spread over 11 years. If approved, the first submarine would be bought for 13 billion baht between fiscal years 2017–2021. The second and third submarines would be purchased during the remainder of the 11-year period. In May 2017, the Royal Thai Navy and Thai Government signed a contract for one S26T variant of the submarine in a $390 million deal. Orders for an additional two submarines are expected in the coming years. Steel cutting ceremony of the first S26T submarine was held on 4 September 2018 at Wuhan, China. :- (See Also : Hangor-class submarine) In April 2015, the Government of Pakistan approved purchase of 8 export version of