Used on our Optoma HD141X, only used three of the arms. Includes all sorts of screws for different applications. No instructions, but there is a video on the product page if you need it. Holds the projector securely. Only part that isn't super are the little quick-release screws. They need an allen key and are a bit tough to put in when working at a height and only two hands. Those would be better as knobs like the ball joint instead. Good value for price when on sale.

Some of the pieces don't seem to fit together nicely, have to tighten everything really tight.

Very easy to setup, fit the projector perfectly and feels very sturdy,