Ditto x2 on all tow bars need to be serviced. I had a brand new one that had to be adjusted after my toad started swinging all over. I would not buy a used one or at least have it looked at by the manufacture before using it.
I'll also just add to buy a auto braking system tow bar.
First time I bought the blue ox tow bar and the brake buddy system.
Had I known more about the inline tow bar braking and some of the other types of braking systems available, I would have NEVER bought the brake buddy.
It sucks getting on your hands and knees to put the brake buddy on the floor of the toad AND taking it in and out all the time.
Do yourself a favor and look into the different braking tow bars. Many members right here on the forum know which ones are the best. Good Luck.