Guess that's what the O scalers are using.

Ran on Ted Schnepf's O scale layout Sunday morning. Quite a layout! Was a lot of fun. Learn right away you are really an engineer when trying to control that amount of weight behing you. Ted got a kick out of us accidently running a passenger train down the engine facility lead. I told him he should say he'd seen it all it after we'd been there a few times!
Clark Propst