AI Prime Flex Arm 12 in — Silicone Flexible Arm Rimless/Rimmed - AquaIllumination

The AI Prime Flex Arm 12in. is the most adjustable mount in the Prime line. AquaIllumination describes it as a silicone-coated flex arm, an attractive and sturdy solution, and their most flexible mount for a rimmed or rimless tank. You bend it by hand, it stays where you put it.

The light is not included.

Why a Gooseneck

A rigid arm gives you two axes of adjustment. A gooseneck gives you infinite. You curve it around a lid, a cabinet edge, equipment that's already installed. And when you rework your aquascape, you re-bend the arm instead of buying another part.

The silicone coating does two things: protects the arm from moisture, and cleans up easily when salt spray dries on it.

Specifications

• Max rim thickness: 1.20in. (30mm)
• Flexible arm length: 13in. (33cm)
• Total overall length: 16in. (40.6cm)
• Coating: silicone
• Cable management: 2 clips included
• Compatibility: AI Prime 16HD Reef, Prime 16HD Freshwater, Prime Fuge

Measure your rim before ordering. AquaIllumination doesn't publish a max thickness on its product pages — the figure above circulates among US retailers. If you're unsure, send us the measurement.

12 or 18 inch?

The 12in. suits nano and mid-size tanks, where the light doesn't need much height. If your tank is deep, you're lighting a sump, or you need clearance above the water, go with the 18in.: its flexible arm is 19in. for a 22in. total length.

One Installation Detail

The set screw in the base lets you twist the arm so the fixture sits flat. Tighten it hand tight only — no tools, no force. And don't bend the arm while it's mounted to your tank rim: take it off, shape it, put it back. That keeps strain off the glass.

What's in the Box

• 1 x 12in. Flex Arm
• 1 x Base screw
• 1 x Base plug
• 2 x Cable routing clips
• 1 x Allen wrench
• 1 x Base mounting gasket

Light not included.

Flex Arm, Tank Mount, or Hanging Kit?

• Flex Arm: the most adjustable. Bends by hand, works around obstacles.
• Tank Mount: the sturdiest and most precise. Two adjustable arms and a ball joint.
• Hanging Kit: the most discreet. Nothing on the tank, everything at the ceiling.

Why Choose ReefSolution

Authorized AquaIllumination dealer in Canada with technical support in French. Picking the mount is the most common mistake on the Prime line — send us your tank dimensions and rim thickness and we'll tell you which part to order. Shipping across Canada.

Complementary products:

• AI Prime 16HD Reef Black — the nano reef fixture this arm is built to hold: 59W, 24 x 24in. coverage
• AI Prime Flex Arm 18in. — the long version: 19in. arm, 22in. total, for deep tanks and sumps
• AI Prime Tank Mount Black — the rigid ball-joint mount, if you want it to never move
• AI Prime Fuge 16HD — the refugium fixture: same housing, same mounting

Frequently Asked Questions

Does the AI Prime Flex Arm work with the Prime Fuge?

Yes. The Prime Fuge, Prime 16HD Reef, and Prime 16HD Freshwater share the same 4.88 x 4.88in. housing, and all Prime hardware fits all three. The Prime Flex Arm won't fit Hydra fixtures though — there's a separate Hydra Flex Arm for those.

Should you get the 12 or 18 inch Flex Arm?

The 12in. (13in. arm, 16in. total) covers most nano and mid-size tanks. The 18in. (19in. arm, 22in. total) is for when you need height: deep tank, refugium in a sump, or extra clearance above the water. If you're torn, send us your tank height.

What rim thickness does the Flex Arm handle?

Up to 1.20in. (30mm) according to the spec sheets circulating among retailers. AquaIllumination doesn't publish this figure officially, so measure your rim before ordering. Send us the measurement if you're unsure.

Does the arm hold its shape once bent?

Yes, that's the point of a gooseneck: it keeps whatever shape you give it. One installation tip — bend the arm before clamping it to the rim, not after. Forcing an already-mounted arm puts strain on the glass for no reason.