I'm a big fan of K&F products in general, they always seem to balance affordability with excellent quality. I already have the larger K&F suction cup mount which I am a big fan of, but while it works perfectly fine for large and small cameras, its size can be overkill for small action cameras and it is quite large in some smaller spaces. This 3" version is very similar, with the same excellent build quality and similar features, just in a smaller footprint.

The system starts with a suction-cup mount that has an air pump that creates a vacuum, making the suction hold very strong. If the suction starts to wane a bit, there is an indicator marking on the button to let you know to add more suction. This gives a sense of safety that you can monitor. On the mount there is also a small hole for adding a rope or cord if you want to tie off the mount to something and add another layer of security in case it should break free. Very thoughtful design.

The ball mount arm has a great lever that twists tight and has really no play, no extra movement once it is tight. The base has holes that are standard 1/4"-20 threaded holes which are the most common for accessories, and the ball mount has the same screws for mounting to the base and to your tripod hole on your camera or whatever other accessory you want to add. Included is also a spring-loaded phone mount which works very well, and an action camera mount that is pretty standard.

Great, strong, well-designed mounting system. I use this for mounting an action camera inside my vehicle, to the windshield mostly but also to side windows. The great benefit is, it is not permanently mounted, so it is so easy to remove and mount in a different spot anywhere else at any time. I've used a lot of mounting systems and most of them have been semi-permanent, affixed with tape or to the dash, so being able to have so much flexibility is refreshing.