MR16 bulb base reference
MR16 is a 12V low-voltage bi-pin spotlight that requires a transformer or LED driver — it is not a mains-voltage base like GU10.
Exact specs
| Designation | MR16 (GU5.3 pin base) |
|---|---|
| Pin spacing | 5.3 mm (GU5.3) |
| Voltage | 12V AC/DC (requires transformer) |
| Reflector diameter | 2 inches (50 mm) |
| Typical wattage | 5W–50W LED/halogen equivalent |
What fixtures commonly use it
MR16 is found in track lighting systems with a 12V transformer, recessed low-voltage downlights, and landscape lighting systems.
What it's interchangeable with
MR16 LED bulbs replace MR16 halogen bulbs in existing 12V transformer setups. Some LED MR16s work with dimmable LED drivers; confirm compatibility before purchasing.
What it's NOT interchangeable with
MR16 is not interchangeable with GU10. GU10 runs on mains voltage and has a different pin lock mechanism. Installing an MR16 bulb in a GU10 socket will not work and may damage the bulb.
Common mistakes
- Buying GU10 bulbs for an MR16 track system — the pins will not engage.
- Assuming LED MR16 is compatible with an old magnetic transformer — check for an electronic driver instead.