So I heard a different, and very interesting, description of a "packer" but you might ask on the transgender forum to be sure.

My understanding of a "packer' was that it could be temporarily worn by a person undergoing sexual transition from woman to man. It is supposed to give them a more proper clothing fit in men's pants as well as the feeling that they have something hanging between their legs (packing). I assumed it was more of a therapeutic device than a sex toy although I guess it could be used for that as well.