I bought a few used ones before, and some of them have a low ringing rate! ! ! And there are many kinds, so it's best to try before making a decision. Besides, this thing has a time limit. I didn't know it at the time, but it won't work after a while!

I know that ludong university Girls' Apartment 1 is sold in the telephone supermarket below. Many people buy it from there, and the price is reasonable! I don't know the specific phone number.