A wizard ring made from silver.  A large odd light blue crystal is mounted on it.  It takes the place of a typical wizard's focus and is more discreet.  A wizard wearing the ring can cast with the focus on their hand doesn't require components nor a held focus.  

Notes: Gypsy Ring of Sleep is a silver ring with a heart shaped Ruby. As an action, the wearer of the Ring can activate the Ring and target one creature. The target must succeed on a DC 18 Wisdom saving throw or be put to sleep 8 hours. The Ring can only be used by a Gypsy and after a long rest.