Answer:
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.
I come with a train and go with a train and the train doesn't need me but can't go without me.
The sun bakes me, the hand breaks me, the foot treads on me, and the mouth tastes me. What am I?
Wind and cord combine, buzzing in the box. In all this we find, though to some the use is lost. What am I?
What goes up and down, but does not move?
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?