How may I obtain a replacement bulb?

I inspect nuclear power plants for a living and bought an Energizer® LED Inspection Light Hardcase a couple of years ago and nothing beats it in toughness and reliability! In my job a reliable, batteries are longer lasting, and brightness are a necessity.That light has been through the mill...dropping it from a good height, gotten wet, name it!!!

It has suddenly died on me and suspect the bulb needs replacing (of course I tried several new batteries). I've tried the big box stores and nobody carries the bulbs. I'd like to put it back to good use and suspect the bulb needs replacing unless there's some other issue I'm unaware of.