Made by manufacturer JinYun, this one has 21 nylon strings- and most notably, the fixed bridge at the tail is split into four separate bridges. It mimics the different lengths of string the S-bridge creates, but (I assume) has a different set of tradeoffs. I have yet to see the difference this choice makes first hand. If you have any experience with one of these instruments, please email me! I have also seen the tail bridge in three parts, so please don't think four is the only way to go.
From manufacturer JinYun. Google is raising security alerts when I visit their website so I won't link directly. You can see their url in the photo and I can tell you that the product number is 01118.