GU10 Base
A twist-and-lock spotlight base with two pins spaced 10mm apart. Runs on mains voltage (120V/240V) — no transformer needed.
GU10 is a bayonet-style base where you push the bulb in and twist to lock it in place — two stubby pins with thickened ends catch in the socket. The "10" refers to the 10mm spacing between the pin centers.
The key advantage of GU10 over GU5.3 is voltage: GU10 runs directly on mains voltage (120V in the US, 240V in Europe/UK), so there's no transformer needed. This makes installation simpler and eliminates a common source of LED compatibility problems.
GU10 spotlights are one of the easiest halogen-to-LED upgrades. The bulb is the same size and shape, uses the same socket, and needs no rewiring. Just twist out the old halogen GU10 and twist in an LED replacement. The LED version will use about 80% less electricity and last 10-25 times longer.
Specifications
| Pin spacing | 10mm |
| Voltage | 120V (US) / 240V (EU/UK) |
| Connection | Twist-lock (bayonet style) |
Related Terms
- GU5.3 Base
A bi-pin base with two pins spaced 5.3mm apart, used for low-voltage (12V) MR16 spotlight bulbs. Requires a transformer.
- MR16 Bulb
A compact multifaceted reflector bulb 2 inches in diameter, commonly used in track lighting, display cases, and landscape fixtures. Usually runs on 12V.
