The 1.5KE6.8CAHB0G: The 150 A peak pulse current at that waveform gives you the headroom for a direct clamp on a 12 V bus with a 5.8 V standoff. Clamps at 10.5 V maximum at the rated current — that keeps the downstream silicon below its abs-max rating on a nominal 12 V rail with transients up to 150 A. The 6.45 V minimum breakdown means it starts conducting before the protected circuit sees overvoltage.
Automotive qualification and temperature envelope
AEC-Q101 qualified — this part has passed the full automotive stress suite: temperature cycling, HTRB, H3TRB, and ESD.
Package and rework reality
DO-201AA axial leaded package — through-hole, so it survives hot-air removal and re-solder without pad lift. The body is large enough to read the marking after reflow, and the leads are thick enough to take a second bend if you need to adjust the standoff height on the board.