Simtac bulb It seems like you might be referring to a SimTac bulb, which is likely a type of automotive or motorcycle light bulb. SimTac could be a brand or specific product line related to LED bulbs, indicator bulbs, headlight bulbs, or other lighting options used in vehicles. However, there isn't specific widely-known information about "SimTac" bulbs, as they may be a niche or regional brand, or the name could be misspelled or abbreviated in some way.