15 years ago, I had a gimmick that fit into the breast pocket which would switch one card for another. Made of high-impact plastic, box shaped, interior had a metal bar separator and length of fishing line for an actuator. (<em>apologies to moderator if description is in violation of revelation policies - I simply do not know how else to describe my dilemma; will happily rephrase if needed</em>)

My questions: Does anyone remember this? Is it, or something similar (delivers the same effect via same or alternate method) still available? And probably what I should have led with, can someone name it?

Many TIA.

Grannelle
the amazing Gregory