It's .046mm tungsten wire that's heated hot enough to glow white. You try and make it durable. You can buy "rough service" light bulbs: http://www.bulborama.co

It's .046mm tungsten wire that's heated hot enough to glow white. You try and make it durable. You can buy "rough service" light bulbs: http://www.bulborama.com/Turbo-Life-20-000-Hour-Light-Bulbs-c34/ http://www.bulborama.com/Turbo-Life-20-000-Hour-Light-Bulbs-... They are, of course, much more expensive per-unit.