The B-curve (4 A) means the magnetic trip activates at 3 to 5 times rated current — 12 to 20 A — so it clears short-circuits fast while tolerating the inrush of resistive loads like lighting and heating elements. The 1+N pole configuration switches the line conductor and provides a switched neutral — the neutral pole opens and closes with the line pole, so the circuit is fully isolated when the breaker is off. This is standard for single-phase final circuits where disconnecting the neutral is required by local wiring rules.
The packaging dimensions (90 x 18 x 80 mm) and single-piece quantity unit mean it ships as a single unit, not a reel or multi-pack.