KTC S091 Monitor Arm Help: Compatibility, Installation, Adjustment, and Safety

Check monitor and desk compatibility, install the KTC S091 arm, adjust its load tension, and keep the mount secure during use.

Quick Answers for the KTC S091

The S091 supports monitors from 23.8–42 inches weighing 2.5–9 kg, with 75 x 75 mm or 100 x 100 mm VESA mounting holes.
Choose a desk clamp or grommet mount. The clamp is the default assembly.
For installation, use a desk 10–60 mm thick. A grommet setup needs a prepared hole 10–30 mm wide. If your desk is thicker, contact our support team to confirm compatibility before installing.
The load adjustment must be made with the upper arm held horizontally. Increase tension if the monitor drops; decrease it if the monitor rises.
Inspect mounting screws and stability at least once every three months.

How Do I Check Compatibility Before Installation?

Check the monitor's weight without its original stand, screen size, and rear VESA hole pattern. The S091 supports 2.5–9 kg, 23.8–42 inches, and 75 x 75 mm or 100 x 100 mm VESA. Confirm that the desk is stable and strong enough to support the arm and monitor over time. Do not use the arm on an unstable or vibrating surface.

Use a desk 10–60 mm thick. If your desk is thicker, ask our support team to confirm the supplied clamp's fit before installing it. Do not force the clamp.

What Parts Come With the S091?

The main parts are the head assembly, upper arm, lower arm, and clamp base. The package also includes grommet mounting parts, a reinforcement plate, M4 screws, thumb screws, washers, and a hex wrench. Lay out the parts before starting. Keep small parts out of children's reach.

How Do I Choose Clamp or Grommet Mounting?

Use the clamp setup on a compatible desk edge. For a desk with a prepared 10–30 mm hole, use the grommet mounting parts. In either case, check the 10–60 mm desk-thickness range, protect the surface with the supplied contact pads, and tighten the base firmly without damaging the desktop. Keep the monitor inside the desk footprint; do not rotate it beyond the desk edge.

How Do I Assemble the S091 Arm?

Install the clamp or grommet base for your desk.
Insert the lower arm into the base and tighten its locking screw.
Insert the upper arm into the lower arm and tighten its locking screw.
Insert the head assembly into the upper arm and tighten its locking screw.
Confirm every connection is secure before attaching the monitor.

Have another person help attach the monitor to reduce the risk of dropping it. Keep fingers clear of moving joints, and avoid overtightening screws.

How Do I Attach the Monitor?

Turn the monitor off, unplug it, and remove its original stand using the monitor's stand-release instructions.
Choose the supplied VESA screws that fit the monitor's threaded-hole depth; add washers where needed.
Install the upper VESA screws, leaving a temporary gap so the monitor can hang on the head assembly.
With another person supporting the monitor, hang it on the head assembly.
Install and tighten all four VESA screws. Check the connection before letting the arm carry the full weight.

Do not force a screw that does not fit the monitor's hole depth. Follow the monitor's own rear-mounting requirements.

How Do I Adjust the Arm's Load Tension?

Hold the upper arm horizontally before adjustment. If the monitor sinks, turn the load adjustment toward + in small steps until the upper arm can hold its position. If it rises on its own, turn toward -. Recheck after each change and do not loosen or tighten the adjustment excessively.

The head assembly also has a separate up-and-down tension adjustment. Make small changes while supporting the display, then confirm that the screen stays in the position you choose.

How Do I Move the Monitor and Route Cables?

The S091 allows tilt, swivel, and screen rotation. Move the display slowly while supporting it with both hands. Leave enough slack in power and video cables for the full range of movement, and route them through the arm's cable channels. Do not let the monitor or arm overhang the desk edge.

How Do I Remove the Monitor Arm?

Raise the monitor to its highest position first. Support and remove the monitor, then remove the upper arm, lower arm, and base in that order. Unplug and free the display cables before disassembly. Keep the screws and small parts together for later reinstallation.

Troubleshooting S091 Installation Problems

The monitor slowly drops or rises

Confirm that its weight is within 2.5–9 kg. Hold the upper arm horizontal and adjust its load tension in small steps: toward + if it drops, toward - if it rises. If the head tilts instead, check the separate head-tension adjustment.

The arm or monitor feels loose

Stop using it while loose. Support the display, then check the base, arm locking screws, head assembly, and all four VESA screws. Do not overtighten. Recheck at least every three months.

The clamp or grommet does not fit the desk

Check that the desk is 10–60 mm thick and, for a grommet mount, that the prepared hole is 10–30 mm wide. Do not force the mount onto an incompatible desk. Contact our support team if you need to confirm the fit of a thicker desk.

Frequently Asked Questions

Can I use the S091 with a monitor under 2.5 kg or over 9 kg?

The S091 supports a 2.5–9 kg load. A monitor outside that range may not hold position safely or allow proper tension adjustment.

Does it fit a 75 x 75 mm VESA pattern?

Yes. The arm supports both 75 x 75 mm and 100 x 100 mm VESA patterns. Verify the monitor's hole pattern and screw depth before installing it.

How often should I check the hardware?

Inspect the arm and mount at least once every three months. Check sooner if you notice wobble, a change in position, or a loose fastener.