Jeremy Karyn Lynnette Marcus Nelly: Review Of Casio Protrek ALT-6000, ALT-6100, PRG-70, PRG-110, PRG-130, PRG-200, PRG-270, PRG-550, PRW-3000 G-Shock G-1250, G-1400, PRW6000, GPW1000, GWG1000
Shaun Cuff på Twitter: "This weekend's #VintageWatch is a #Casio ALT-6000 Alti-Thermo. Launched in 1992 this was Casio's first twin sensor watch. Along with the ATC-1000, they were forerunners to Casio's #Protrek
Vintage Casio Alt-6000 Alti-Thermo Digital Watch - Near Mint! Pre Pro Trek | WatchCharts
Vtg Casio Watch Men Twin Sensor Alti-Thermo Black 950 ALT-6100 New Battery | eBay