Clamping specs and what they mean on the bench
The SMAJ24CA-13-F: The 24V reverse standoff voltage means it stays out of the circuit below that rail — the clamping kicks in at 26.7V minimum breakdown and holds the transient to 38.9V max at the 10.3A peak pulse current. That clamp voltage is what the downstream silicon sees; if your 24V rail feeds a regulator rated for 40V abs max, this part buys you margin.
Board-fit and temperature envelope
Surface-mount DO-214AC (SMA) — the same footprint as standard SMA diodes, so it drops onto existing pads without a layout change. No power line protection (the part is a standalone transient suppressor, not a rail clamp with integrated filter). It's a general-purpose TVS for signal and low-power supply lines where a fast clamp is needed.