Cannondale is one of the few manufacturers with documented serial number meanings.
Downside, there's 6 different serial number schemes from 1983 to current.
And your number doesn't match any of them, but 1999 comes closest with:
E=1993, F=1994, G=1995, H=1996, I=1997, J=1998, K=1999
A=January, B=February, C=March, D=April, E=May, F=June, G=July,
H=August, I=September, J=October, K=November, L=December
But there is no month code for "S"
More info at https://vintagecannondale.com/info/serial_numbers/
Thing is, this info tells you very little, and nothing useful outside of an original-spec rebuild.