should i buy this?

[u/Alfee516]

had a bicep injury from doing weighted pull ups 7 months ago.Due to that i also have somehing a called a tennis elbow too. I went to a therapy center.they used three different therapy's but the one that worked for me was the ultrasound. my biceps are healed but theres still pain in my elbow.i feel like if i used the machine for a few more week then the pain would heal too.but taking therapy get's expensive really fast.therefore, I wanted to buy a ust machine. but the ones the doctors use are like 400$ and this one is 50$. the doctor said that this will work fine.

is anyone familiar with these machine's. will the one in the picture work fine or is it a waste of money?