This adapter is for the Sweepa Broom head so I could attach it to my standard pool poles. It's a standard broom handle thread but smaller in diameter. I use it for cleaning my solar cover and it helps with opening and closing the pool. I like the Sweepa broom because it's a soft head that's completely made of rubber so it won't damage anything.

Sweepa Head:
https://www.amazon.ca/Sweepa-Rubber-Broom-Head-Only/dp/B00SS2ZNCW/ref=sr_1_1?ie=UTF8&qid=1507551393&sr=8-1&keywords=sweepa