The SMBJ110E3/TR13 is a Zener-type transient voltage suppressor — it clamps fast overvoltages on a 110 V rail to 196 V maximum at a 3 A peak pulse current.
Clamp voltage and pulse current — the real protection envelope
The 196 V clamp at 3 A peak pulse is the hard ceiling the downstream circuitry must survive — if your 110 V rail has a 200 V-rated capacitor on it, this TVS will not save it. Breakdown occurs at 122 V minimum, so the part starts conducting before the rail reaches 122 V, giving the clamp headroom to hold at 196 V under full pulse current.
No package obsolescence risk on this form factor.