This is a very high quality ceiling mount that was bought in the USA. It was originally designed primarily for dental and medical settings but can also be used for residential settings. We used this to mount a television in a bedroom. It has a gas spring which allows the screen to be lowered through 90 degrees. The screen can be rotated and tilted.
The vesa mount is for 80x80mm and 100x100mm but can be adapted with vesa adaptors (which we did for use with a Samsung television). The vertical pole is 3 feet (36) or approximately 90cm long. This mount has been lightly used in a private residential situation (and rarely handled and adjusted).