These are the official connectors made by Philips that come with the Lightstrip Plus 2 meter/6 ft base kits.
They are designed to be used with V4 of the Lightstrip plus so that you may connect together 2 sections of Lightstrip Plus that have been cut along the cut marks where there is no 6 pin header to make the connection.
Sold as either a 3-pack or 10-pack.
NOTE: The connectors are not compatible with earlier versions of the Lightstrip Plus, as the pin spacing is smaller on the V4 strip.