Prisoners tested BMW E46

Increased and reinforced high traction studs Lancia Delta 2000 16v diameter 12mm X 1.25

High traction studs that ensure a correct closure of the cylinder head on the engine with the usual thread and stock diameter.

Prisoners high traction for Ford Sierra / Escort Cosworth 12mm

Prisoners high traction for Suzuki Hayabusa engines in 1300

Reinforced head studs Lancia Delta Fiat COUPE 2000 16V Turbo high traction which ensure correct closure of the head tested up to 530 hp on Lancia Delta engine with usual thread and diameter as standard.

Prisoners high tensile guaranteed at least 550hp on engine Lancia Delta

High traction reinforced head studs for Fiat 500 Abarth engines Fiat Fire or Fiat T-Jet Abarth, Panda 100hp engines and all Fiat fire 8v engines and similar engines.