Excellent solution for video work whilst driving. or for a very secure tripod mount that you can keep in your vehicle full time. That's where I keep it now.
The suction works very very well...I could not budge it in any way. I would trust my gear on it.
The base is solid metal...very stout...with a plethora of attachment points. Also included is a small camera mount that keeps stable using O rings. I think I would definitely feel confident with a 'GoPro' type product with this mount, but I'm going to balk at using my full frame camera on it.
Which leads me to a very slight ding and suggestion to K&F. It's a great design, but if K&F had simply added a male to male short thread to go into the base...then I could add my mount on it. That is exactly what I ended up doing. Luckily I was able to purloin the needed male to male connector off of one of my travel tripods. Once that is inserted into the base, then anything you want to add to it...ball head...fluid head...even a gimbal is now possible. I don't think the added weight is any concern to the product...it's grip is a beast.
You can see the ball head I attached in the provided images...now that is a nice set up.
Excellent product otherwise...and still a strong 5 stars.

Recommended.

The cost of this vacuum/suction mount is very reasonable for a 6 inch suction. The rubber suction is thick durable and malleable enough to secure to surfaces that are not completely flat. The solid aluminum base has several 1/4 20 mounting holes, 3/8 mounting holes Arri location anti-twist holes and the top of the aluminum base has angled sides for more versatility with mounting options. Adding to the versatility is the accessories, the fully metal magic arm, the GoPro adapter and the phone adapter makes for a lot of options to mount different accessories. This suction cup is very easy to use, place the rubber suction on a clean surface give the plunger a few pumps until the safety line on the plunger disappears and its ready to go. Because of all of the holes the accessories the wide base makes this suction very functional.

THIS is a serious piece of hardware. I kind of scoffed when I saw a full-size DSLR attached to this suction cup.. thinkin' "no way".. but boy was I wrong. This thing is truly a serious suction cup mount. It WILL hold a full-size DSLR. I don't know if I would suction cup it to the hood of a car doing 90mph with a 4000 dollar camera on it, but it certainly holds harder than I expected. Holy cow.

In picture: Canon 5DSR with a Sigma 600mm mirror lens. Is it heavy? It's heavy enough.

I think you could literally pull dents with this suction cup.

When you first take it out of the box it's obvious this is a well built piece of kit. I've been needing a mount for the hood of my van since none of my magnetic mounts work there. This does the job perfectly! It's rare that I use anything on the outside of the van other than an action cam but I wouldn't hesitate to mount a mirroless or DSLR on here depending on the lens used.

The phone holder it comes with is trash but other than that it's a great mount and a great deal.

This K&N Suction Cup Base is top notch. The materials and machining of the base are spot on perfect. Tons of mounting options to accommodate just about any piece of camera or lighting gear I could think of. Ive used this to mount my DJI Action 5 to my Jeep with awesome results and am currently using it in the cabin of my sailboat to document projects where floor stands would clutter things up.

Great design with plenty of uses and applications!

I recently picked up the K&F Concept 6" Suction Cup Camera Mount with Magic Arm for some dynamic car shots and it's quickly become one of my favorite tools in my kit. I own some other K&F gear and I like all of it. The 6" suction cup holds extremely well on smooth surfaces like car hoods, windshields, or glass. I tested it on a long highway drive and it never budged. The included articulating arm gives you a lot of flexibility for adjusting camera angles on the fly. Great for POV shots or getting creative perspectives. Both the suction cup and the arm feel solid and reliable. I had no concerns about mounting a mirrorless camera (Sony A7 series) with a mid-range lens. If you're looking for a dependable camera suction mount for automotive video work, product shots, or time-lapses, the K&F Concept model punches well above its price point. Just clean the surface, mount it properly, and you're good to go. Definitely recommend for vloggers, filmmakers, or content creators on the move.

Immediately upon opening the box you can see how beefy this thing is. The rubber and metal is thick, the ball arm has a robust knob and a spring to lock it down. I think just about every part of this is made of metal except for the rubber base and the pump button. The ball mounts have an extra ring of rubber to keep them tightly locked. There are 1/4“ and 3/8” screw holes all over the base to add accessories. There is a hole on the base to add a cable or cord if you want an extra level of security between the base and a mounting area. The whole design was clearly not an afterthought, they put some time into making a quality product that has a lot of versatility and usability.

The suction seals very easily and sticks extremely well. There's no way to pull it off without intentionally releasing the suction. The air evacuation pump to create suction works really well and I really like that there is a white line on it; if you see the white line, it is an indication that you should add suction.

If I could improve one thing it would be a bigger mounting plate on the camera side or a mount that would be Arca-swiss compatible. The camera mounting plate is pretty small, which is perfect for small action cams or for the included phone mount, but for larger cameras it would be less shaky if it had a larger surface. As it is, it would be easy to add one to this existing design by adding another mounting plate or getting one with a built-in ball mount (these are 20mm diameter balls) so I'm not taking off any points for that.

I was a little afraid I did some tests before actually putting my room at risk and despite a few holes it held up perfectly, but be careful and do the right tests before each shot. 100% approved

As a holder for the Starlink mini antenna, you are top quality and fits together with the adapter that I also bought here

I tested it intensively with mirrorless, action cameras and smartphones, and I can say without hesitation: it's a professional product, and you can see it right from the start.