Hello Don -
Are you SURE you need a flexible hose? My trailer does not use one. It uses two rigid (ABS) tubes that telescope. One is larger than the other, so the two fit together and as the top is raised, the larger half of the tube simply slips over the smaller half, but the two stay joined when the top is up. Then, when the top is lowered, the smaller slides back into the larger diameter tube so that the resulting composite tube is shorter.
I can't recall anyone on this forum talking about a flexible "stink pipe". However, I'm sure if there is one, someone will be able to correct me.
- Jack