Is this homebrew magic item, the Necklace of Peer Pressure, balanced?

The intent of this item is to provide a version of the spell Suggestion that is stronger than the base spell but not as powerful as Mass Suggestion. The party members who would receive this item will be 5th-7th level, this item may be used in or out of combat. Is this item appropriately balanced for use as a rare item?

Necklace of Peer Pressure

Wondrous Item, Rare (Requires Attunement)

Casting Time: 1 action

Range: 60 feet

Duration: 12 hours

This appears to be a necklace made of polished puka shells. In order for the abilities of the necklace to be activated, the necklace must be worn and clearly visible. The necklace can hold a maximum of seven charges, and it regains one charge each dawn.

When the necklace is activated, you cast a version of Mass Suggestion with the following limitations:

You suggest a course of activity (limited to a sentence or two) and expend one or more charges to magically influence up to seven creatures (one creature per charge expended) of your choice that you can see within range and that can hear and understand you.

The necklace regains one charge each dawn. Each target must make a DC 15 Wisdom saving throw. On a failed save, it pursues the course of action you described to the best of its ability.