Double-ring ceremony - prohibited by Rav Moshe Feinstein זצ''ל

Sydney Rabbi writes:

I am surprised that none of my Melbourne colleagues knows of the Tshuva by Rav Moshe Feinstein ז''ל where he clearly and unambiguously writes that it is assur for the bride to give the groom a ring under the Chuppah. They should look it up themselves in Igros Moshe, Even HaEzer vol 3, siman 18.