Alessi12701 E & B Pitch-Pipes for 9091 Sapper Kettle

What are the differences between the alessi 12701 e & b pitch-pipes for 9091 for $18 and the $190. 9091 kettle do they sound different ???

Which pipe goes on top and which goes on the bottom?

Is spring included w/ pipes, can it be bought separately?

How do I replace the pipes? Which one goes on top?