Our take
GN21B-SILVER offers two USB-A ports, SD and microSD, and a USB-C charging path for a compatible laptop. Resolve the source disagreement on PD wattage and confirm the current model offer before relying on it.
A USB-C laptop user who needs two USB-A data ports and both card formats, can verify the 30W/60W power conflict, and does not need video, Ethernet, or iPad charging from the data ports..
It is not the right choice when you need a settled charging limit, HDMI, Ethernet, an included charger, Apple SuperDrive support, iPad charging from its USB ports, or a verified direct offer for the historical ASIN.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- B&H identifies the exact GN21B-SILVER model and documents two USB-A ports and both card slots.
- The hub uses a USB-C PD pass-through connection for compatible devices.
- The source documents selected compatibility and notes its SuperDrive and iPad charging limits.
What to weigh up
- B&H and Protronica conflict on the charging limit: 60W versus 30W.
- B&H marks its model listing discontinued, and historical ASIN B01BUHY5DY is unmapped.
- No HDMI, Ethernet, or included charger is documented.
Specifications and exact model details
The key details
| Model covered | GN21B-SILVER |
|---|---|
| Host connector | USB-C host |
| USB 3.x data ports | Two USB-A data ports up to 5Gbps are listed |
| Installation | Five-in-one USB-C adapter with SD and microSD readers |
| Hub power | Separate hub power supply or included charger is not documented |
| Host charging | USB-C PD pass-through; sources conflict between 30W and 60W, host output unknown |
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
The card and USB mix is its main distinction
GN21B-SILVER combines two USB-A ports with separate SD and microSD readers and a USB-C pass-through charging connection. It is a useful mix for a compact laptop setup where the user alternates between common peripherals and memory cards. The five-in-one marketing name refers to these output functions; the integrated host connector is not another downstream port. Both B&H and Protronica describe the model as a slim aluminum hub for USB-C devices and MacBook users. B&H says it was designed to sit flush with the 12-inch MacBook. The listing also warns that Apple's SuperDrive is unsupported, and its USB-A ports should not be treated as charging outputs for an iPad.
Read the USB speed as a shared interface ceiling
B&H lists two USB-A ports at up to 5Gbps and an integrated USB-C host interface at 5Gbps. That is the advertised interface rate, not a promise that two connected drives will each sustain 5Gbps simultaneously. Actual transfer rates depend on the host, connected device, cable, file type, and concurrent traffic. The page does not provide an independently measured result. If you mainly connect a mouse, keyboard, or flash drive, the two-port expansion may be enough. For repeated large file transfers, verify the current product's port labels and use a host connection that supports the listed generation. Avoid counting either SD slot as another USB port when comparing capacity.
Resolve the conflicting charging figure before relying on pass-through
The two inspected product records disagree about the USB-C charging limit. B&H describes a 60W Power Delivery connection, while Protronica lists a smart charging specification of 14.5V at 2A, or 30W. Because both records name GN21B-SILVER, this is a material source conflict rather than a reason to select whichever number is more attractive. Confirm the current model label and its documentation before using the hub for a laptop that requires a specific wattage. A pass-through socket also requires a separate compatible charger; neither source establishes that one is included. Do not assume the host receives the full input rating after hub power use.
Check device support and special peripheral limits
B&H lists selected MacBook generations, iPad Pro and iPad Air versions, Chrome OS, and Windows systems with appropriate USB-C or Thunderbolt support. Those lists are a starting point, not a universal guarantee for every device with a USB-C connector. The host port must support the required data function, and video is not listed as an output for this five-in-one model. B&H specifically says Apple's SuperDrive is unsupported and the USB ports will not charge an iPad. If either device matters, choose another hub or check a current product manual before buying. The page does not list Ethernet, HDMI, or audio connections, so this is a card-and-peripheral adapter rather than a monitor dock.
Search the exact model and confirm the current offer
B&H marks its model page discontinued, while the source does not map historical ASIN B01BUHY5DY to GN21B-SILVER. The tagged Amazon search is a model search, not a direct claim that this historical ASIN remains active. Compare the listing's silver finish, model code, two USB-A ports, SD/microSD readers, and the PD rating stated on the live offer. Ask the seller or manufacturer to resolve the 30W/60W inconsistency if charging is essential. A current offer should also confirm whether accessories are included; the sources do not establish an included charger. This review uses product-page specifications only, not personal tests, buyer-review summaries, current price, stock, or sales data.
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Before you buy
How many USB-A ports are listed?
B&H lists two USB-A data ports for GN21B-SILVER.
Is the PD rating settled?
No. Sources state 30W and 60W.
Does it support Apple's SuperDrive?
B&H states that Apple's SuperDrive is unsupported.
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.
- B&H GN21B-SILVER HyperDrive model listing ↗ — checked October 4, 2026.
- B&H identifies GN21B-SILVER, its five-in-one layout, port rates, device limits, compatibility, and discontinued listing status ↗ — checked October 4, 2026.
- Protronica GN21B-Silver listing gives a 30W charging figure at 14.5V/2A ↗ — checked October 4, 2026.
- Historical Amazon ASIN page returned a cache miss; current exact offer mapping is unverified ↗Paid link · We may earn a commission. — checked October 4, 2026.
Is it the right fit?
Check the exact model and today’s offers on Amazon.