Antimagic Manacles

In addition to functioning like normal manacles, these manacles also prevent their wearer from casting any spells. When applied to a creature, it falls under the effect of an antimagic field. 

Applying the manacles on a willing creature takes an action. To apply them on an unwilling creature, make a Strength (Athletics) check contested by their Strength (Athletics) or Dexterity (Acrobatics) check (their choice). Additionally, a creature may break the shackles of the manacles with a successful DC 25 Strength (Athletics) check. The manacles radiate an aura of abjuration magic, as is revealed by the detect magic spell.