Should I believe the guy who wants to sell me USDT at 1:1

[ubunuser]

I want to buy some crypto currency and found local guy here. Over the conversation he said that he can sell me USDT and then I can buy whatever I need to buy for USDT. He said USDT is like USD, the difference is that it is crypto and the ratio is 1:1 plus 10% for his services. So it like I will pay him 1100 USD and he will tx 1000 USDT to my Binance account.

Since I have never heard about USDT, I just want ask you guys is that what he saying is correct?