R18 is a new generation 4G+2G vehicle/motorcycle GPS tracker.
Compare to S20, the differences are:
R18 price is much cheaper
R18 is 4G+2G, S20 is 2G only
R18 is smaller than S20
R18 and S20 functions are almost the same. The R18 doesn't have below functions compare to S20:
1) R18 can't provide specific external power voltage value, only provide on/off status.
2) R18 doesn't support fuel theft/filling alert
3) R18 internal battery working time Max is 2 hours
4) R18 no phone call function, the generated alert can't trigger phone call, only GPRS/SMS options.