Latchkey Rangefinding Monocle

Latchkey Rangefinding Monocle is a sealed optical monocle that measures distance, relative motion, and angle while leaving one eye free for ladders, hand signals, and incoming trouble. It must be zeroed to the wearer and helmet; loaners produce small errors that become large ones across a docking span. Every sighted object enters a rolling cache, so the monocle can quietly become a record of who stood where when negotiations failed. Its modular lock plate accepts cheap third-party tools and expensive authenticated ones with equal politeness. That openness keeps independents employed and gives security departments a recurring rash. Praxis will recertify a transferred Latchkey Rangefinding Monocle, but the bench fee climbs when its shock log has gaps. Salvagers call that extortion right up until a claim depends on the number.