The ice trick works great for cleaning the tank sensors in an RV too, Dump, add ten gallons of freshwater and 3-4 bags of cocktail ice and head down the road!
I should have also said, it's a stamped sheet metal part with no holes to fasten it on, it's a interference fit type deal. If I remember right the brand was stamped in the top of it.
I'm trying to help out a friend here and his trailer is not where I can see it. He has a Extreme triple axle and is missing the top cap for the jack. I think it's about a 02-06 vintage, the trailer for my DCB had the same jack but the boat has sold now. Any ideas?