You'll need a special USB-C to HDMI cable, rated for Thunderbolt speeds. I recommend and have purchased this Uni Thunderbolt to HDMI cable from Amazon, which is about $16. You can find cheaper options, but make sure they're rated for either Thunderbolt or a 4K@60Hz display.

I'd recommend a Thunderbolt 4 dock. You can score a deal as retailers continue to clear out old Thunderbolt 3 inventory, but they're being phased out. You can always future-proof your setup with a Thunderbolt 5 laptop and dock. but those aren't essential quite yet.

Thunderbolt 5 is the 80Gbps version, which backwards compatible with both Thunderbolt 3 and 4. Thunderbolt 5 isn't something to worry about quite yet. (I've even tested a Thunderbolt 5 setup, and didn't like it. Even the Thunderbolt ecosystem doesn't seem convinced that Thunderbolt 5 will become a thing for a couple of years.) However, I think it's the fault of an early test laptop, and not the spec itself. Thunderbolt 5 will happen.

I'll detail some of the differences between the specifications below. But if you're new to this, let us reiterate: Thunderbolt 3 and 4 are basically the same, and Thunderbolt 5 won't be an issue until after 2025.

Essentially, Thunderbolt 3 and Thunderbolt 4 allow up to 40Gbps maximum bandwidth, enough for two 4K/60 displays. "Up to" is the key phrase: Thunderbolt 3 is only required to support a 10Gbps connection, allowing for a single external 4K display (a 16Gbps PCIe connection, paired with USB 3.2). Most manufacturers go beyond this, however, and our recommended docks support the full 40Gbps specification (and two 4K displays) unless noted. Thunderbolt 3 also supports a slower (16Gbps) PCIe connection for connecting to external storage.

Thunderbolt 3 is also the only specification (not Thunderbolt 4) that we've seen connecting to external GPUs, in case you'd like to try that approach. Thunderbolt 5 adds that capability back, but I haven't seen anything that really takes advantage of it.

Thunderbolt 4 doesn't allow for any leeway—you're getting a full-fledged 40Gbps connection (32Gbps PCIe + USB 3.2), no questions asked. For external storage, Thunderbolt 4 supports 32Gbps of data transfer—this really only matters for video, external GPU connections, or possibly games. Thunderbolt 4 supports "wake on sleep" from an external keyboard or mouse, which allows you to tap your external keyboard or wiggle your mouse to wake up your PC, which is handy. Thunderbolt 4 allows for longer cables and more Thunderbolt ports on laptops, too.

Device maker Anker has a nice table of all of the technical features associated with Thunderbolt 3, Thunderbolt 4, and USB4, if you really want to get into the fine distinctions (below). What's USB4? We address that further down.

Virtually every Thunderbolt dock will ship with its own cable. We recommend that you use Thunderbolt 3 cables with Thunderbolt 3 products, and Thunderbolt 4 cables with Thunderbolt 4 products. Ditto for the first Thunderbolt 5 cables, when the technology ships.