About
Kestner Supply is a US company that manufactures power and connectivity hardware — at two factories we own, in China and Vietnam. We grew up on the factory floor, so we build and test from the inside; you buy from an American company and reach one person who owns the outcome.
Most companies that sell imported power and connectivity hardware to US buyers are brokers. They find a factory, mark up the invoice, and disappear once the container clears. We are the factory.
We own two factories — one in China, one in Vietnam — where the boards are populated, the cable is molded, and every unit is tested before it ships. We grew up on that floor; it is the standard we build to, and we don’t sell anything we can’t inspect and warrant ourselves.
Because both plants run the same drawing set, we can build the same part in either country — and almost nobody offers that from a single accountable company. Same drawings, same test reports. You choose the country of origin — and when the tariff schedule moves, as it has repeatedly in the last eighteen months, you move your volume without requalifying a supplier, re-listing a UL file, or explaining anything to your own customer.
And you don’t buy it from an overseas factory. You buy from a US company, in dollars, on US paper, and reach one person who owns the outcome. If a shipment is late, you call one number and a person picks up. That is the part a broker can’t copy and an overseas factory can’t offer: the plant is ours, and so is the accountability.
We only sell what we can inspect, warrant, and stand behind. If something is not a fit, we say so — plainly, on the first call.
ChinaPower & cable
SMT, magnetics winding, injection molding, and 100% final test under one roof — AC/DC adapters, switching power supplies, and cable assemblies.
VietnamChina-plus-one
The same drawings and the same UL file as China, with a Vietnam country of origin — so you elect origin without qualifying a new supplier.
HTS 8504.40
AC/DC power adapters, GaN chargers, and switching power supplies — standard or custom power supply builds to your voltage, connector, and enclosure.
Explore power →
HTS 8544.42
USB-C, HDMI, Ethernet, coax and fiber cables, hubs, and custom cable assemblies — molded, terminated, and tested on our own lines, to the same standard as the power hardware.
Explore connectivity →
The factory floor is where we learned the trade — how a real production line runs, what a good part looks like, and how to test one before it ships. Our two plants are the core of what we sell, and the standard we hold everything to.
They are not the ceiling. When you need a power or connectivity part we don’t make ourselves, we don’t hand you off — we source it through a factory we’ve vetted the way we run our own: a line walk, the test data, the mill certificates, and an approved sample before a single unit ships.
What we make or what we source, the accountability doesn’t move: you contract with Kestner, and Kestner warrants what ships. Nothing we can’t inspect, warrant, and stand behind.
The floor, not the ceiling
The certifications below are the minimum every order already clears — where we start, not where we stop. Held at the manufacturing level, each is verifiable by file number on request.
cULus Listed
cRUus Recognized
cETLus (Intertek)
CE
FCC Part 15
RoHS
REACHcULus ListedcRUus RecognizedcETLus (Intertek)CEFCC Part 15RoHSREACH
The principal
I grew up around this business. I can tell you what the injection-molding line sounds like and how long the ICT test takes, because I have stood next to both. I studied economics and psychology at the University of Chicago, then went back to the work I actually knew.
Kestner is not a person. It is a name I picked because it sounds like the big American brands our factory sells to — the names I grew up hearing about.
My given name is 尚烨. It happens to sound almost exactly like 商业 — the Chinese word for commerce. My parents deny doing this on purpose.
Shangye (Mike) LiPrincipal, Kestner Supply
A manufacturer. Kestner owns two factories — one in China, one in Vietnam — and builds power adapters, chargers, switching power supplies, and cable assemblies on its own lines. We make the goods, test them, and warrant them; when a part falls outside what we make, we source it to the same standard rather than hand you off.
Yes — two of them, one in China and one in Vietnam, running the same drawing set and test procedure. That is what lets you elect the country of origin without requalifying a supplier or re-listing a UL file.
Yes. You contract with an American company, in dollars and on US terms, and reach one accountable person — while the manufacturing runs at our own plants in China and Vietnam.
On our own lines in China and Vietnam, under one engineering system and test procedure. You choose the country of origin, documented per unit.
Power adapters, chargers, and switching power supplies; USB-C, HDMI, Ethernet, coax, and fiber cables; USB-C hubs; and custom cable assemblies — standard SKUs or built to your drawing.
Tell us what you need, or come see the plant behind your build — in China or Vietnam, by appointment. We don’t charge for it, and we don’t stage it.