161 spells out AFA, Anti-Fascist Action, using letter positions in the alphabet: 1 for A, 6 for F, 1 for A. It's been a quiet signal across the European anti-fascist scene for decades. Low-key to outsiders, crystal clear to comrades.
Stitch it onto a battle vest, a bag or the knee of your jeans. Four sizes mean there's one for every gap.