GE Classic 50-Watt EQ MR16 Soft White Gu10 Pin Base Dimmable Halogen Light Bulb (3-Pack) in the Spot & Flood Light Bulbs department at Lowes.com
EXN-GU10/12V Halogen MR16 50W
LUXRITE MR16 LED Bulb 50W Equivalent, 12V, 2700K Warm White Dimmable, 500 Lumens, GU5.3 LED Spotlight Bulb 6.5W, Enclosed Fixture Rated, Perfect for Track and Home Lighting (6 Pack) - Amazon.com
Feit Electric 50W Equivalent MR16 GU5.3 Bi-Pin Dimmable 12-Volt Track Lighting 90+ CRI LED Flood Light Bulb, Bright White (144-Pack) EXN/930CA/6/24 - The Home Depot