The only thing KITT has to deflect the Laser's bolts are a set of High Tinsel Reflectors.
("KITT vs. KARR")
The Laser was also referred to by Michael and KITT in "Knightmares". The Laser Power Pack seems to be a updated form of the Resonating Laser first used in "Trust Doesn't Rust".
The Laser button was later made into two buttons for Season 3 and 4: Arm Laser and Aim Laser.