1993-1995 do not have the o ring seals on the shaft part of the opti. 1996-1997 did have them. The optical trigger on the opti is actually the "reliable" part of it. what tends to fail more often then not is the cap and rotor. The people who are running the coil-on-plug setups (LTCC, Delteq) are ditching the rotor part of the opti and keeping the optical trigger.
