Plugable UD-ULTC4K review

Verdict

For a base M1 or M2 Air, the UD-ULTC4K is the documented way past Apple's one-monitor limit. Plugable says it connects three displays even when the computer supports only one on its own, as long as DisplayLink Manager is installed. The trade-offs are the usual DisplayLink ones: an app that needs Screen Recording permission, and no HDCP for protected video.

Pros

• Plugable documents extra displays on M1, M2, M3 and M4 Macs through DisplayLink, beyond the Mac's native limit.
• Up to three displays at 4K 60Hz, over HDMI or DisplayPort in any mix.
• 100W charging (96W certified to the host) from the included 135W adapter.
• Gigabit Ethernet, SD, four USB-A and a front USB-C port.

Cons

• Needs DisplayLink Manager, admin rights and macOS Screen Recording permission.
• HDCP is not supported, so protected video may not play.
• M5 is not in Plugable's supported chip list.
• Plugable's page gives macOS 11 and macOS 10.15.7 as the minimum in different sections.

Best for

MacBook Air with M1 or M2 that needs two external monitors, on a Mac where you can install apps.

Skip if

Your Mac is managed and blocks installs or Screen Recording, you watch protected streaming video on the external monitors, or you have an M5.

View on Plugable

Score breakdown

The overall score is the weighted average of six criteria, each scored 0 to 10 from documentation. See the rubric

1. Mac compatibility documentedWeight 30%7/10

   Lists Apple M1, M2, M3 and M4 (base and Pro/Max) and macOS 11 or later. M5 is not listed. Minus 1: another section says macOS 10.15.7 or newer. Source 1

2. Two monitors on MacBook AirWeight 25%8/10

   Connects three displays even when the computer supports one on its own, with DisplayLink Manager installed: 2 points each for M1 to M4. M5 is not documented. Source 1

3. Display modesWeight 15%8/10

   Up to three displays at 4K 60Hz over HDMI or DisplayPort, on hosts with DisplayPort 1.4 Alt Mode or better. Source 1

4. ChargingWeight 10%10/10

   Up to 100W, 96W certified to the host, from the included 135W adapter. Source 1

5. Ports and connectivityWeight 10%8/10

   9 downstream ports: USB-C 10Gbps, four USB-A 5Gbps, SD, headphone and microphone jacks, Gigabit Ethernet. Source 1

6. Software and limitsWeight 10%3/10

   DisplayLink Manager is required, with admin rights and Screen Recording permission. HDCP is not supported. Source 1, Source 5

Works with your MacBook Air

DisplayLink screens sit outside Apple's native count, which is why this dock can add monitors on an M1 or M2. Plugable does not say which output is native and which is DisplayLink in every case, so the result column gives the total it documents.

What DisplayLink asks of you

• Install DisplayLink Manager yourself. Plugable says installation on macOS is manual and needs administrative permissions. Its driver table lists DisplayLink Manager for macOS 14, 15, 26 and 27 (dated September 18, 2026).
• Allow Screen Recording in System Settings. Plugable says the permission lets the driver send the picture over USB and that nothing is stored or recorded.
• Expect no protected video on these screens. Plugable states HDCP is not supported, and its knowledge base explains that protected content may not play while a DisplayLink display is active.

Our native video vs DisplayLink guide covers the login-screen and managed-Mac cases.

Specifications

As published by Plugable. Values in this table are the maker's, not measurements.