BoBH

Deep Lead Dagger

Weapon finesse, light, thrown (20/60 ft.) Uncommon

Melee weapons and ammunition made of or coated with deep lead are unusually effective against spellcasters, disrupting their concentration. Whenever a creature takes damage from a deep lead weapon or piece of ammunition and is concentrating on a spell, it has disadvantage on the saving throw it makes to maintain its concentration.

Cost: 302gp Weight: 1lb