This is the CSI/DSI cable extender from Adafruit. It is a simple module that allows you to connect two 15-pin 1mm pitch cables together. You simply connect the cables to the connectors and click them into place. In theory, the CSI/DSI interface is not intended for super long cables. The module has been tested with two 1 meter cables. That worked, but beware success is not guaranteed. CSI/DSI is in principle for approx. 25cm.