Needing a replacement sewer hose donut seal

Several days back I went to install my regular sewer hose and discovered I no longer have the donut seal; fortunately I had a screw on type back up hose.

Numerous options: https://www.amazon.com/s?k=rv+sewer+foam+collar&ref=nb_sb_noss

My initial thought is to purchase (one) each - the cheapest for backup and the most expensive for use; but figure I'd better served by first seeking opinions ...

foam or rubber? any input from avoidance to strong recommendations?

And if you want a free one visit Foley AL, its last known use.

I guess this is a dirty subject; being impatient I just ordered the two referenced seals.

If I discover anything significant about either one I'll report back.

How do you use those donut thingy's exactly? Was at a CG that didn't have screw in connections and bought a donut, tried it, and threw it out as I didn't feel comfy w/ it.

Wish the guy next to me would have used one. Whew 😡

Most RV parks have a store with RV stuff as well as some food items. They almost all have that donut seal. Walmart has them as well as Camping World. You can find them on line at Amazon as well as Ebay. Only had to use ours five for six times in five and a half years. In most places where a donut seal is required, they post a statement the it is the law that the sewer connections must be sealed. That being said, I have seen some not sealed and obviously loosely enforced.

Just in case there's any followup interest, here they are: my $2 seal (left) and my $22 seal (right).

As you can see the cheaper one is thicker. I suspect the more slimmed down seal will fit in to the opening deeper.
They're both reasonable hard but the fit and finish are obviously different (I don't believe that'll make any difference in use).

Next trip out I'll do a real world test.

Last week at the Elkhart campground there was some plumbing problems on one row. Ended up being one of those donuts underground between the septic and that row.

I lost mine in (Sweet Home) Alabama so don't go blaming me for that <Grin>.