Sending a chastity device abroad

I possess an item from that I intend to have modified so it works with ‘s locking mechanism. I’ve talked this over with them, and I am prepared to send my device to Poland from the United States.

I feel a bit anxious since I have never sent anything across borders before, let alone a chastity cage. I think I need to declare what is inside on a customs form. At first, I was going to label it as “jewelry,” but the link below indicates that mailing jewelry to Poland is not allowed.

Does anyone have ideas on how to describe it or other tips to keep problems to a minimum?