Treadmill That Folds Under The Bed What Is The Best Treadmill To Get?

What is the best Treadmill to get? - treadmill that folds under the bed

Hello, I try a treadmill, but I do not know much about them. My biggest concern is that the folds and can under the bed or behind the sofa. I am looking to sell on treadmills, which is what I see, or be careful when I check-out to make sure I am one, that is not broken, should I? What functions will have at best or need? Thank you.