Bewm!’s Alarm

You set a bomb alarm against unwanted intrusion. Choose a door, a window, or an area within range that is no larger than a 20-foot cube. Until the spell ends, an alarm alerts you whenever a Tiny or larger creature touches or enters the warded area. When you cast the spell, you can designate creatures that won't set off the alarm.

When Bewm!’s alarm is activated all creatures 20 foot cone in front of the bomb roll for damage.Each creature within a 20 foot cone of the exploding fragmentation grenade must make a DC 15 Dexterity saving throw, taking 5d6 piercing damage on a failed save, or half as much damage on a successful one.

Can be dismantled and get parts back.