Lighting guide · 1 October 2026
GU10 or MR16? How to Tell Which Spot Bulb You Have
Two spot bulbs with the same face and different pins. Tell them apart in ten seconds, then pick the wattage.
Same face, different base
Hold a GU10 and a low-voltage MR16 side by side and the fronts match. Both have a reflector 2 in across. That shared shape is what MR16 means: a reflector 16 eighths of an inch wide. The difference is at the back.
A GU10 has two short pins that end in flat feet. You push it in and turn it, and it locks. An MR16 for 12 volts has two thin straight pins, called GU5.3. It pushes straight in and pulls straight out.
The voltage follows the base
The base is not only a shape. It tells you the voltage. A GU10 socket is wired to 120 volt house power. A GU5.3 socket sits behind a transformer that feeds it 12 volts.
This is why the two cannot swap, even with an adapter in hand. A 12 volt bulb on house power fails at once. If your fixture has a transformer, or it is a landscape light, you want the MR16 with GU5.3 pins. A candle warmer lamp, a range hood or a line-voltage track head takes a GU10.
Then choose the wattage
Once the base is settled, read the fixture's label for its top wattage. Our GU10 halogen comes in 25, 35 and 50 watts. The MR16 halogen comes in 20, 35 and 50 watts. Buy the number on the label or lower.
The table lists every Vinaco bulb with the MR16 shape. Use it to check the base, the voltage and the light output before you open a page.
| Bulb | Base | Voltage | Watts | Lumens | Dims | From |
|---|---|---|---|---|---|---|
| Vinaco GU10 Halogen Bulb, 120V Dimmable | GU10 | 120V | 25 to 50W | 220 to 500 | Yes | $13.91 |
| Vinaco GU10+C Halogen Bulb with Glass Cover, 120V | GU10 | 120V | 25 to 50W | 220 to 500 | Yes | $6.99 |
| Vinaco GU10 LED Bulb, 5W 120V | GU10 | 120V | 5W | 450 | No | $16.94 |
| Vinaco MR16 Halogen Bulb, 12V GU5.3 | GU5.3 | 12V | 20 to 50W | 300 to 800 | Yes | $18.26 |
| Vinaco MR16 LED Bulb, 7W 12V GU5.3 | GU5.3 | 12V | 7W | 450 | No | $12.20 |
Halogen or LED in the same socket
Both bases have an LED version in our catalog. The GU10 LED draws 5 watts and the MR16 LED draws 7. Each keeps the pins and the shape of the halogen it replaces.
Neither LED dims, and neither makes much heat. Keep halogen on a dimmer and in a candle warmer. Use the LED where a light burns for hours on a plain switch.
