This is the second 18in flexarm I have had in the past ~8yrs on tank and I have had no issues at all. The newer design with the full panel screw clamp piece makes it more sturdy than the single one before and as long as its tightened down well and just aware that it can move with major pressure, its easy to work with and position. I have not had an issue with my light falling in the tank at all and been happy with the purchase!

I'm another purchaser that had my lights drop into the water. Don't do it. Mount your lights some other way. Wish I had read these and chose a different mount for my brand new lights

Purchased 4 of these and all four have the same issue, the rubber pad that grips the aquarium comes loose and the whole thing falls into the tank. do not buy.

The head that goes into the light strips very easily and forces you to use some type of adhesive to hold the light in place securely. Also, the hex screw screws into plastic which also strips very easily. The mount itself is very solid and easily adjustable but the materials that need to be torqued need to be improved.

Like the title says the screw straps very easy bit that being said spoke with AI customer service and after a quick picture and an email they replaced the the base free of charge. The other reviews of people losing their lights in the water sucks, but everyone in the hobby should know you need at least a net lid on your tank because 90% of all saltwater fish jump. A cheep $20 lid would have saved a $200 light.

Not sure what the negative reviews about this mount are about. The only gripe I have about it is the screw that holds the arm to the mount. It is of very low quality and is easily strippable since it adheres to plastic and not metal. Other than that it is a solid mount and comes with cable organization clips.

I was a bit worried when i decided to order this, but upon installing it is a solid mounting option. It feels very secure on my rimless tank. The arm is easy to adjust and holds firm. I have zero concerns about this holding my light in place.

3 days after installing this my light ended up in the tank. What a joke, ruined my brand new $200 light. Sure hope I can get somewhere with AI on this.

I was worried about the instability of the clamp from day 1. Had it screwed on the back of my new IM Fusion 20 as tight as possible, within a week the single plastic clamp screw had twisted off the black backing film on the tank. Within 1 month the Prime had tipped over into the tank. Thankfully it do not fry my fish.

This failed 3 weeks after it was installed. My light went for a swim and is now worthless. Not a happy camper!

It is hard to believe AI could make a light this nice and then sell this POS as the mounting bracket. Make the bracket an inch wider and add a 2nd screw and it would probably work great. As is, it is TERRIBLE!!!

The arm is a bit difficult to work with such a small screw on an 18" arm, I would look for an alternative flex arm. I got it to work with a little tinkering. But I have a screen atop my 20g tank. so if it decided to go for a swim the screen will stop it from falling into the tank. Surprised at AL they put out such nice LED fixture but this mounting option needs some work.

Better than their than their original mount design for this Prime light. I bought the 18 inch for my 10 gallon IM Fusion tank and it's too long. I will go with the 12 inch for the 10 gallon and save this 18 inch for my Red Sea Reefer.

Stay away from this mount. As another reviewer said, there is a single plastic screw used to secure the mount to the back of your tank. It bends as you screw it in so the light will not be secure on the tank. If you dont have a lid, expect to buy a new light in 2 months guaranteed. It WILL fall in eventually. I cant believe they havent recalled this yet honestly.

At first, I thought this would be ideal, having the flexibility of the adjustable arm. However the plastic mounting bracket broke within 12 hours of being on my tank.

This arm really is the best option to-date for the AI Prime. It's not perfect, but I've not had any troubles mounting it. Unlike a previous reviewer, it does not slide around on the glass. Cord management works pretty well. Yes, you can see it from one point of view to another, but it's not looking like a kid's science project!

The flex arm is alot better than the static mount. The set screw on the bottom can be tricky but not any worse than the problems with the light set screws on the other type of mount. Take note that the pictures do not show the cord, it runs down the flex neck with included Clips. It is visible when mounted.