A brallet is a bra-wallet
The Brallet is a very light wallet that can be plugged and fastened in the bra. The idea is that during your activities (dance, sports, etc) your pass (s) and money are stored securely. The Brallet is designed for the moments when you don't have a bag or pocket, and makes the bags rollers a lot more difficult. The Hema has a cleavage wallet in the assortment, and came forward during a HEMA design competition.
Https://www.youtube.com/watch?v=62GYJRtbS5Q