Simply Conserve Corn Cob 16800 Lumen EX39 Base 400-Watt EQ ED17 Daylight Ex39 LED Light Bulb (2-Pack) in the General Purpose LED Light Bulbs department at Lowes.com
Light Efficient Design 120W LED - Replaces 400W HID - 9929 Lumens - E39 Base - 4000K - UL Type A | ProLampSales
LED Retrofit Lamps for Metal Halide 400W Replacement
80W LED Corn Light Bulb, 250W-400W Metal Halide Equal, 5000K (Daylight White), EX39 Mogul Base, 9,956lm, Step-Dimming, 100-277VAC, UL-Listed, Warehouse, High Bay, Workshop, Post-Top Light Retrofit - - Amazon.com
LED High Bay Retrofit - 400W Equal - RAB HID-115-V-EX39-840-BYP-HB-G2 | CityLightsUSA.com