A corn bulb can have the right wattage and still be the wrong lamp. This guide matches Keystone corn bulbs to 70W–400W metal halide lamps and lists each lamp's length, diameter, enclosed-fixture compartment, and temperature rating, plus the ballast bypass steps.
Most wall pack callbacks come from glare, a photocell fighting a time clock, or the wrong voltage. This guide covers full cutoff vs. traditional, an HID-to-LED wattage swap table, photocell and 0-10V options, CCT, and mounting, with in-stock Keystone, Euri, and LeanLight SKUs.
If you’re still running metal halide or high-pressure sodium fixtures in warehouses, parking lots, or high-bay applications, there’s a better option available today. LED corn bulbs