It's a bell housing bolt,holds the gear box to the engine. More importantly it's connected to an earth strap. Make sure you tighten it ASAP, if it comes loose it may cause sparks and other bad things

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Marti


Car: C Red S13 Silvia 2.3l 400+rwhp-SOLD
Daily ae82 4age corolla (light mods)-Sold
Daily:SWB GQ Patrol
Will be a 03-04 STI next