Our take
UCN3303-1 is primarily a dual-HDMI display adapter for a compatible USB-C host. Its macOS mirroring behavior and ambiguous Windows dual-display modes need to fit the planned screen setup.
A USB-C laptop user who needs HDMI connections and can verify DP Alt Mode, host generation, operating-system behavior, and the exact display mode..
Avoid it when two independent external desktops on macOS or guaranteed dual 4K output are essential, or when the computer lacks DP Alt Mode.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- Two HDMI outputs and one USB 3.0 port are listed
- Separate USB-C PD input up to 100W is specified
- The maker documents host requirements and macOS mirroring
What to weigh up
- Requires a capable USB-C Gen 2 or Thunderbolt host with DP Alt Mode
- macOS mirrors two external screens
- Windows dual-display resolution wording is inconsistent
Specifications and exact model details
The key details
| Model covered | UCN3303-1 |
|---|---|
| Host connector | USB-C Gen 2 or Thunderbolt 3/4 host with DisplayPort Alt Mode is required |
| USB 3.x data ports | One USB 3.0 data port is listed |
| Installation | Portable cabled adapter; maker lists a travel pouch, but current package should be checked |
| Hub power | USB-C PD input up to 100W is listed; separate hub adapter is not specified |
| Host charging | Maker states about 8W is used by the adapter and about 92W reaches the host |
Performance figures are manufacturer claims. Source checked October 4, 2026. Regional models and included accessories can differ.
Full review: how the features affect your choice
What the features mean for you
Two HDMI sockets serve a narrow, well-defined purpose
UCN3303-1 is primarily a compact display adapter for a computer that has a capable USB-C video connection and needs HDMI screens. UtechSmart lists two HDMI outputs and describes a four-in-one arrangement that also includes USB 3.0 and a USB-C charging input. That mix is useful when an otherwise thin laptop has few built-in connectors. It is not an Ethernet dock or card-reader hub, and the maker does not list those functions for this model. Buyers should compare its exact connector set against the devices they plan to use rather than rely on the broad four-in-one label.
The host port must carry video
A USB-C socket by itself does not guarantee that an adapter can send video. UtechSmart tells buyers to check for a USB-C Gen 2 or Thunderbolt 3/4 port and DisplayPort Alternate Mode, and says this adapter does not support USB-C Gen 1. That requirement should be checked against the computer’s own specifications before purchase. The adapter cannot add video capability to a data-only USB-C port. The brand also lists USB 4 as compatible, but a buyer should still confirm their particular computer and display configuration against its video-output limits.
Treat the display ceiling as a single-screen figure
The main specification describes HDMI up to 4K at 30Hz for one display. UtechSmart’s dual-screen FAQ contains mixed language: it says the adapter displays to two monitors, then separately says Windows supports a single HDMI display up to 4K/30Hz and discusses a 1080p dual-display mode elsewhere in the product information. That makes the simultaneous resolution for a two-screen setup a point to confirm, not a safe assumption. A buyer who needs a guaranteed dual 4K workflow should choose a device whose manufacturer clearly specifies that exact mode for the intended host.
macOS mirrors external screens
UtechSmart explicitly says macOS supports mirror mode for the two HDMI screens rather than two independent extended desktop spaces across those external monitors. It says a MacBook can extend to one external screen, while two external screens display the same content. This is a meaningful difference between a mirrored presentation or duplicated work surface and independent multi-monitor productivity. A Windows buyer should also verify the computer’s graphics and USB-C capabilities, because the listing’s mode descriptions do not guarantee the same outcome across all hosts. Do not infer OS support from the two physical HDMI sockets alone.
USB data and Power Delivery have separate roles
The one USB 3.0 port is listed for data transfer up to 5Gbps, and the separate USB-C connector is identified as a PD power input up to 100W. UtechSmart attributes about 8W to the adapter and says about 92W reaches the connected computer. These are the maker’s listed power-path figures, not an independent measurement. The USB data port is not presented as a second charging connector. Buyers who need charging should check that their charger uses USB-C Power Delivery and compare the host’s requirements with the exact product notes.
Confirm the seller’s exact UCN3303-1 version
The manufacturer page lists model UCN3303-1 and repeats the historical ASIN B07X5KSBNJ, which helps identify what product the old record referred to. It does not establish that an Amazon page currently offers the same model, seller configuration or package. The tagged search route uses the exact model number and dual-HDMI description. Before ordering, compare the physical port diagram and verify that the listing says UCN3303-1, includes the needed USB-C PD input and supports your host’s video mode. The maker page lists a travel pouch, but package contents should still be confirmed on the selected offer.
Who should consider it
This is a candidate for a USB-C laptop owner who specifically wants HDMI connections and understands the host and operating-system conditions. It is less suitable when the buyer needs independent dual screens on macOS, confirmed dual 4K resolution, Ethernet, SD readers or a documented host charging wattage. Those needs are not covered by the product’s supported evidence. Compare the output mode and port list with the actual workstation plan before choosing it. This buying assessment uses the manufacturer’s specifications and support answers, not personal testing or buyer-review summaries.
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Before you buy
What model is it?
UtechSmart identifies the adapter as UCN3303-1.
Does it support two separate extended displays on macOS?
The maker says the two external screens mirror rather than showing independent content.
What host support is required?
The maker specifies USB-C Gen 2 or Thunderbolt 3/4 with DisplayPort Alt Mode.
How much of a 100W input is listed for the host?
UtechSmart attributes about 8W to the adapter and about 92W to the computer; those are maker figures, not test results.
Where can I check the current price?
Use the Amazon link for current offers. Check the exact model, seller, product condition, delivery, and return terms. This page does not display a live price or confirm stock.
Sources and review basis
Sources & review basis
We use the linked product documentation for the features above. Our suitability notes and buying advice are editorial judgments based on those features, not measured performance results.
- UtechSmart official UCN3303-1 product page ↗ — checked October 4, 2026.
- UtechSmart model, port map, host-video requirements, HDMI modes, macOS behavior, and 100W input/about-92W host power split ↗ — checked October 4, 2026.
Is it the right fit?
Check the exact model and today’s offers on Amazon.