I purchased two 12" arms along with the Prime 16HD. The updated mounting foot provides great coverage to clamp to glass. Light screwed in with no problems and wire management hooks are great. The 12" allowed the light to be 8" from the water and centered on my Innovative Marine 75 EXT. If you need higher than 8", would recommend the 18" arm.

Great product! Cheap easy to set up and gets the job done!

What ever you do, do not snug down the light when installing. You will strip the threads off the flex arm in a heart beat. Definitely not impressed with the quality of this mount.

I purchased a pair of these mounts for my 40 gallon one month ago. I have been having problems since day one with these. I thought I could make them work, and I made the decision to keep them based purely on aesthetic purposes. I can tell you that it was a huge mistake. Within the month, the rubber pads on it would continue to slip off the bracket holding the mount to the tank and the light would be sliding to the left or right. I would readjust it everyday. And then within the month the mount failed and I lost my light. Do not buy this, opt for the ceiling mount if you can, it will save your light and save you money. This is not BRS’s fault, i just can’t believe AI would stand behind such a terrible product. My light is toast..

I purchased a pair of the 12" flex arms two years ago. I just had one of the brackets separate into two pieces without warning sending the light crashing into the tank. Luckily I was in the process of setting up a new tank, and it didn't have water in it yet. Otherwise, this could have been a much more expensive disaster. I see based on the pictures on BRS, that they have altered the design of the bracket since I purchased mine. I can only hope the new design is an improvement. On mine, the front and back of the bracket are constructed from two distinct pieces of plastic snapped together, and the connection between them is what failed. There was some hardened brittle glue inside where they separated along with some broken plastic connection points. I can't imagine why they would not have chosen to make this part from one solid piece of plastic. I hope that's the case with the new design. Hard to tell from the photos.

I was very hesitant before purchasing three of these to put over my red sea reefer, but during and after install and stretching lights over my open top tank I felt confident that they would work just fine. These grip onto the glass tightly and the arm is screwed into the light, so very secure. They haven't budged since I set up 4 months ago. I wouldn't recommend stretching these out as far as possible but instead having a slight bit of arch. I really don't understand what is causing peoples lights to fall in their tanks. If used properly, and this seems quite easy to do, you will have no problems.

Hanging arm is a Piece of Crap. *20000%. I little touch boom light in the tank. Broke off with a little touch. Do NOT buy this at all if you do not want to loose a AI light. I CAN NOT believe that the company even sales this crap.

Best trochald light ive had in my squiliam life

I bought one of the first Primes for my 6g nano tank. It's been on one of their tank mounts which uses a ball joint and clamp assembly to attach to the light that was difficult to get tight and stay in place. It finally failed completely and was impossible to tighten to where it held the light. This flex mount screws directly into the light and is essentially one piece, and is waaaaay better than the tank mount I had.

BRS was backordered on this mount so I ordered from another company, sadly! Anyway, owning this flex mount and the rigid elbow mount, I prefer the flex mount. More compact, modern, rubber coated, and attached in 2 minutes. Same rim attach mounts on both devices. It probably would not support any more weight than the AI Light. For the price point, I am very happy. I love the minimalist look. May have to swap out my rigid elbow mount as the flex is really nice aesthetically.

I have 2 of these on 2 different tanks, both 12" arms. I've read of others having problems with them, but I don't move my lights around much and I've not had a single issue with them. I could see the 18" length being a bit more finicky due to the length, but I don't have experience to say that.

These looked awesome. However, they are really easy to over tighten when you're installing them onto your tank. As a result the screws that hold the unit together get ripped out of the plastic threads. Once they are damaged it's nearly impossible to repair them. All in all, I ended up going with the square brackets for the AI Prime which are much sturdier and only slightly less attractive. It really came down to protecting the value of the lights; which I really didn't want to take a swim in my tank.

I think the goose neck looks great and it stays in place, easily adjustable does what its supposed to and looks good doing it. The plastic screw it comes with used to attach the mount to the tank is wicked tight and i needed to use pliers to tighten it on. Once on it worked great.