Suppose you have a laptop with a usb-c connector, which you on a beamer to connect to. Big chance that you have a verloopstukje need, such as the usb-c-to-VGA-converter of Ewent.
This supports a maximum resolution of 1920 x 1080 pixels, full hd. It Is not sufficient, then sells the company is also a converter with hdmi connection, which has the same cost price.
Usb-c to 4K
It supports 4K, which can be useful when you the notebook to link to a display with that high resolution. Both adapters are sold for 24.50 euros per piece.