Dual Monitor Arms

Most dual arms in the range use two independent arms on one post or base. Each screen moves on its own, so you can angle one towards you, push the other back, or set them at different heights. This suits screens that differ, and anyone who moves one screen more than the other.

A crossbar carries both screens on one beam with a single arm behind it, as on the Zgonic ZGX-DS, Ergotron HX Desk Dual, HAT Collective E5 Dual Crossbar and Humanscale M8 Pro Dual. The pair lifts, lowers and swings together and stays aligned, which suits two matched screens used as one wide display.

A stacked layout puts one screen above the other on a pole, like the Ergotron LX Pro Dual Stacking and HAT Collective E5 One-over-One. It uses less desk width, at the cost of a higher top screen.

Look up the weight of each monitor without its stand, from its spec sheet, and compare that figure with the arm’s range. Most dual arms are rated per screen, not for the pair combined, so two 6 kg monitors need an arm rated to at least 6 kg on each side.

Check the minimum as well as the maximum. A spring or gas arm set for a light screen can drift upwards if the screen is below its range, and a heavy screen on an arm rated just under it will sag. Where a maker publishes only a maximum, as HAT Collective and Humanscale do for several models, treat it as the upper limit and confirm a light screen on the product page or with us.

Size limits are the maker’s, and some depend on whether the screen is flat or curved. As a rough guide to width, two 24-inch screens side by side span about 110 cm and two 27-inch screens about 125 cm, before any gap between them. Bezels and stands vary, so measure your own screens. Two 27-inch screens are wider than a 120 cm desk, which arms can manage by reaching past the edges, but a 140 to 160 cm desk leaves room to angle them.

Pairing a laptop-sized second screen with a large main monitor, or an older screen with a newer one, is common. Independent arms handle this best: each arm is set to its own screen’s weight, and you line up the top edges by adjusting each arm separately. A crossbar expects two similar screens at the same height, so it suits a matched pair better than a mixed one. Check that both weights fall inside the rating, and that both screens share a VESA pattern the arm accepts.

A portrait screen beside a landscape one is useful for code, documents and long web pages. Check that the arm’s head rotates through 90 degrees and that the rotated screen clears the desk and the other screen; a tall screen in portrait needs the arm raised higher than you might expect. For a stacked pair, the top screen sits well above eye level for most people, so it works best for reference material you glance at, or with a smaller screen on top.

Dual arms fix with a clamp over the desk edge, a grommet through an existing cable hole, or a bolt-through fixing in a drilled hole. Measure the thickness of the desktop where the arm will sit, and check there is a solid edge behind it with no frame rail or modesty panel in the way. Ranges differ by model, from 10 to 50 mm on the Float Dual to 0 to 65 mm on the CBS Ollin split clamp. Some arms, such as the CBS Flo and HAT Collective E2, are tightened from above the desk, which helps where there is little room underneath. Our desk compatibility checklist covers each check in detail.

A dual arm suits a height-adjustable desk well, as the screens rise with the desktop. Check the underside first: the clamp plate must clear the frame, crossbars and motor housing. Add the arm and both screens to everything else on the desk and stay inside the frame’s rated load. Leave enough cable slack for the desk’s full height travel, and route cables along the arm rather than taut to the floor. Heavier screens reaching well forward add a little wobble at standing height, so a firm frame helps. Our sit-stand desk buying guide covers load and stability, and the sit-stand desk range lists rated loads.