20'-25' flag pole for residential

I put one up for my now late father-in-law about 15 years ago and used a 20 ft. piece of thick walled galvanized pipe. I dug out a hole 3 ft. deep and about 1 ft. around, set up the pole in the hole and poured concrete to fill the hole and made sure to let it come up about 3 inches above ground level.

I leveled the pole and then sloped the cement away from the pole so there was no chance water would hold at the pole's base. His first pole was cemented in the ground but he didn't run it up above the ground and it eventually rotted and fell over due to water rusting the base away.

I used a 3foot long piece of 3 pvc pipe buried it down and installed 2 bags of concrete around it leveled the pipe leaving 3inches exposed once set up i installed a a 2.5 inch aluminum flag pole from Amazon it is 25 foot tall. It is the telescoping type .
It has not moved and looks great.

I purchased a 25 ft aluminum flag pole from these guys LINK a few years back. Truck shipped to my door. Comes with a pvc ground sleeve. Dug hole per their instructions and concreted the sleeve. I called them prior to purchase and they were very helpful.

It was 650ish pre covid. Based on the new prices, covid must have affected the flag pole industry as well.