Guide
LED Track Lights Buying Guide: GU10, MR16 or COB?
It's natural to start choosing LED track lights from a picture of the finished shop or showroom. Fair enough. The dull stuff underneath matters just as much, though: which lamp holder sits inside the head, whether the order is for a finished light or an empty shell, and whether the adapter will actually click into the rail on their ceiling. Get one of those wrong and the lovely sample on your desk turns into a return. So that's where I'd start.
Look inside the head first
From across a room, two track heads can be twins. Same cylinder, same matt black, same little tilt knuckle. Put them on the bench and take the front off, though, and one has a twist-lock socket sitting there waiting for a lamp while the other has a COB module bonded to a heat sink with the driver tucked in behind. Different animals.
The holder is really a question about who gets to change the light later. With a GU10 or MR16 head it's whoever owns the ladder, so store staff, a homeowner, the maintenance contractor. With an integrated COB head it gets decided the day the order is signed, and it stays decided. Then there's E27, which takes a full-size screw lamp, usually a PAR20 or PAR30 reflector type. None of these is the correct answer in general. I'd just rather you picked one on purpose than off a photo.
GU10, the one everybody already knows
GU10 runs on mains voltage in most markets, so the lamp doesn't need separate low-voltage gear. On the assembly line that means a plain body: socket, leads, housing, adapter. Fewer parts to go wrong in the factory. Fewer to go wrong in the ceiling, too.
Shop teams like it because a lamp swap takes seconds and spares are sold pretty much everywhere. Fancy a warmer look over the winter displays? Change lamps and you're done. Wholesalers like it for another reason entirely: one body, lots of lamp choices, and far fewer fixture codes cluttering up the warehouse.
The catch is obvious once you think about it. The lamp decides how good the light is. A nicely finished GU10 head can still give poor light if someone fits a cheap lamp later, and the fixture tends to get the blame. If you order complete GU10 lights, ask which lamp ships inside. If you order housings, that part's yours.
MR16: confirm dimensions and supply
MR16 heads get considered for low ceilings, inside display cabinets and along shelving near eye level, basically anywhere a row of chunky cans would shout. Don't take the size for granted, though. Lamp base and body dimensions vary from one MR16 model to the next, so check the drawing for the exact head you're looking at rather than assuming the format guarantees a small one.
Sort out power before anything else. MR16 has traditionally been a low-voltage format, which means somewhere between the track and the lamp the supply has to be right, and how that's handled changes from one model to the next and from one market to the next. Don't bother comparing prices until you know how the lamp is fed inside the head you're looking at and that it agrees with what your track carries.
After that it behaves a lot like GU10. Replaceable lamps, a format maintenance people recognise, bodies available without lamps. Both holders sit side by side on our GU10 and MR16 track lights page if you want to compare them properly.
COB heads are built as one piece
Chip-on-board just means a lot of tiny LED dies packed into one dense patch. In a track head that patch sits behind a reflector or lens made for it, and the heat has a path out through the body. Hold your hand under a COB head on a shop floor and look at the shadow. One shadow, crisp edge. That's a big part of why COB became the default for accent work on merchandise and artwork.
Because source, optic and driver are engineered together, you're specifying the light once. Colour temperature, colour rendering, beam and output all come baked into the model. Brilliant if you know what the space needs; a bit of a gamble if you don't. Some COB heads have adjustable focus, so the installer can open up or tighten the beam on site, and selected models come in dimmable versions. Our COB track lights page goes through those variants.
And no, a COB head can't sensibly be bought empty. A body without its module isn't a product, and we won't ship one pretending to be.
E27 for bigger lamps and taller rooms
E27 heads are the heavyweights of the family. Full screw base, normally carrying a PAR20 or PAR30 reflector lamp, so the body's bigger to match. You'll find them in lobbies, in high-ceilinged stores, in industrial-look interiors where a slim head would look a bit lost. Like GU10, they come complete or as bodies only.
Finished light or empty housing?
This is the one people skip. Then it bites them at delivery.
A complete light leaves us with its light source decided: lamp fitted, or COB module built in, ready to clip on and switch on. A housing leaves with the holder, body, tilt joint, finish and track adapter. Nothing in that box makes light.
Housings are the sensible route when you've got a lamp supplier you trust, when your market wants lamps you certify yourselves, or when one body has to cover several lamp options across a range. Complete lights suit the installer who wants one box and one sheet of paper.
Whichever way you go, keep them on separate lines in the quote and on the purchase order. I really can't stress that enough. A shell and a finished head aren't comparable on price or on anything else, and lumping them together is how a warehouse ends up with a pallet of empties nobody meant to buy. Our LED track lights catalogue filters by form, so the housing-only series are easy to pick out.
Will it actually fit your rail?
Every head has an adapter, and every adapter is made for one kind of rail. Conventional rails get described by wire system (2-wire, 3-wire, 4-wire or 6-wire) and an adapter from one family won't seat in another. On top of that the head has to suit the track voltage and the lamp it's holding.
A warning, while we're here. Don't read a dimming method off the conductor count. What those wires do depends on the rail, the country and, frankly, whoever wired the building. Dimming gets confirmed model by model against your system, or it doesn't get promised.
Best trick we know? A phone photo of an existing adapter held up next to the end of the rail. It shows the fit far more plainly than a description, and it's quick to send.
Magnetic track, by the way, is its own system entirely. Conventional heads don't go on magnetic profiles, and we don't mix parts between the two.
Get these in writing before you order
Specs drift between models within the same series, so be wary of any figure quoted for a whole family. For each head on your shortlist, ask for the power, the light source (COB, SMD or which lamp type), colour temperature, CRI, beam angle, tilt and rotation range, material and finish, compatible track including wire system, adapter and voltage, and the warranty, which differs by model. Boring list. Saves arguments later.
Certification works the same way. A CE, RoHS or UL mark belongs to one specific model, so check the spec sheet for that exact head instead of assuming the series carries it. And if you need app or wireless control, mention it in your first email rather than your fifth: smart versions exist on selected models, and which platform a head supports is something our team confirms case by case.
If LED engine jargon is new to you, the Zhaga Consortium publishes interface specs for LED light engines and is a neutral place to read up. Lamp caps and holders are standardised internationally as well, through the International Electrotechnical Commission.
If you just want a rule of thumb
Staff or homeowners will be changing lamps? GU10. Tight space, or the heads need to more or less disappear? Look at MR16, once the supply question has an answer and you've checked the dimensions of the exact model. Accent on product or art with a fixed spec and not much maintenance, that's COB. High ceiling or bigger lamps points to E27. And if you already stock or certify lamps yourself, order housings in GU10, MR16 or E27 and fit your own.
Once the holder's settled, beam and quantity come next. The track light beam angle guide deals with spot versus flood on a shop floor, and how many track lights a space needs covers counts and spacing. Or skip all that and send us the rail and the room. We'll come back with a shortlist that has every field above filled in.