On September 12, 2018 H I Sutton at Covert Shores commented that Chinese IMAGE A (below) (also see at the Chinese website) reveals a "stretched KILO" class submarine. This "stretched KILO" might also be a new Chinese class of conventional attack submarine, that more fully incorporates reverse engineered features of the KILO.
This is a bold claim, because the Chinese IMAGE A provided is blacked out, revealing no features on the side of the hull and no positioning evident of diving planes (aka hydroplanes). If the diving planes were on bow/hull this may indeed indicate a KILO (see H I Sutton's IMAGE B).
Alternatively if the planes were mounted on the "sail" (or "fin") this may indicate a YUAN class submarine (see IMAGE C). Note that YUAN style diving planes are indeed mounted on the sail in the upper photos of the Chinese website in question.
Another problem is Chinese IMAGE A (and the other Chinese website photos) conveniently cut any stern "tail" preventing a viewer assessing any lack of an unpright tail fin, indicating a KILO, or the presence of an upright tail fin which may indicate a YUAN (IMAGE C).
IMAGE A - A low quality and only partial Chinese photo at http://bbs.tiexue.net/post2_13224151_1.html
IMAGE B - H I Sutton's drawing of a so called Stretched Kilo with the main distinguishing picture being the lack of an upright fin on a cruciform tail.
IMAGE C. Less exciting, but more likely. An existing YUAN class submarine - a type in commission since 2006 and with a stretched hull that accommodates AIP (This August 2015 photo is from the USNI News site).
The Chinese website photos provide inadequate evidence to claim we are seeing a "stretched KILO". More likely we are seeing photos of an existing YUAN class submarine.