Connected to the outlet pipe of your swimming pool uses a venturi effect to suck surface debris through the nozzle and into a bag.
You will need 39mm (1,5in) diameter hose attached to your pool outlet and into the nozzle and a bag to catch the leaves. Something like an orange (fruit) bag
Apart from a test fit in my own pool its untested
Update:
Its been in my pool for a few days. A weaver decided it wanted to start again and pulled its nest apart dumping it ALL in my pool #firstworldproblems I know because most of it got caught by my leaf skimmer. so it works. I've loaded a few pics one is when I just installed it and one a few days later.

This has been working for a few weeks now and does a fine job. I have identified a few areas to improve and Ive tried to do so playing to the strengths of 3D printing. V2 will be posted as a new project.

If you want to see more and how I create prints and 3D designs like this check out my YouTube channel. https://www.youtube.com/channel/UCSHUc93NXGwBacoIDDqPU2w