Protection envelope — what the ratings mean on the bench
The SMCJ7.5A-13-F: This is a 1500 W (1.5 kW) peak pulse power Zener TVS in a DO-214AB (SMC) package, unidirectional, with a 7.5 V reverse standoff voltage. That 12.9 V clamp is the number to check against your downstream IC's absolute-max rating — if the protected device's max is, say, 14 V, this TVS keeps the transient below that threshold.
Board fit and temperature reach
Surface-mount in the DO-214AB (SMC) footprint — the same pad layout as the standard SMC package used across the industry, so no board spin if you're swapping in from another brand.