4pcs E14 to MR16 Gu5.3 G4 Gu4 Lamp Base Holder Socket Adapter,Euro Standard Candelabra base E14 to MR16 G4 Spotlight Converter|e14 to mr16|e14 tomr16 adapter - AliExpress
Spot led lightbulb with gu4 (or gu5.3) base isolated on white background. focus point on lower part of image. | CanStock
Feit Electric 20-Watt Equivalent MR11 GU4 Bi-Pin Dimmable 12-Volt Track Lighting 90+ CRI LED Flood Light Bulb, Bright White-BPFTD/930CA - The Home Depot
SENCART G4 GU4 GU5.3 MR11 3W 30lm 30-SMD 5050 LED Blue Light Lamp (9~14V) - buy at the price of $1.70 in dx.com | imall.com