Computer Love Records - Casio TM-100 Transmitter Watch Manufactured in 1987. You could use it to broadcast on an FM radio frequency. (📷: pocketcalculatorshow.com) | Facebook
Vintage 1987 Casio TM 100 Radio Transmitter digital watch JDM Japan module As is | eBay
Rare Casio TM 100 Radio Transmitter digital watch JDM Japan module 661 | WatchCharts