Sinotrack ST-904

Sinotrack ST-904 is a compact waterproof personal GPS tracker for kids and the elderly. The device features an SOS button, voice monitor, two-way communication, alerts (movement, speeding, leaving, geofence, etc.), a built-in 1500 mAh battery, and more.

Protocol: sinotrack Manufacturer: Auto Leaders Forum discussion
Properties
Custom command
custom
Send custom command to device without waiting for response, Scheme: "*,,#". You have to specify payload only
payload: Payload string
Mileage query command S32
{"payload":"S32,000000,1"}