Is there a charge for the SOS function on the mobile phone used by the elderly?

I don't know this brand of mobile phone for the elderly. I used elegant devices. At present, there are only four elegant instruments, S7 18, S728, S738, S758 and S7 18. Pressing the SOS key is just an emergency call, there is no positioning function, and there is no charge. However, S728, S738 and S758 have a positioning function. When pressing the SOS key to make an emergency call, the mobile phone will automatically dial the number of relatives and send a message to inform the location of the helper, so the SMS fee and traffic fee will be deducted, which is very low. The general SMS fee 10 to 20 points, depending on your tariff method. The traffic fee is the usual traffic fee, a few cents, not very high. I'm worried about the high cost of buying a cottage, hehe!