A 12mmx1.25 tapered plug, 12mm long, useful for plugging the air injection port(s) on DOHC and SOHC engines.
Allen socket head.
Gives a clean, professional look. Hard to find!
Fiat X19 / 128 1300cc (1974-76) - 4 required for head
Fiat 124 Spider, 131, Lancia Scorpion, Lancia Beta (1974-78) - 4 required for head
New and unused.