YouN USB 3.1 Type-C Female to Female Coupler USB-C Converter Adapter Connector

Inexpensive and simple way to connect and extend your USB-C cable. It's also lighter to carry this and another USB-C cable around with your Apple MacBook than an HDMI cable (if you're using it to extend the connection to a screen/projector) and/or a mains cable (to extend a charger lead).