I've used this for over a year for both cats and kittens. It never came with official instructions, so here's my guide on how to use the arm and hammer sifting litter box. I also put this litter box inside a medium Home Depot box (then on top of a litter mat) as it's a cheap $2 way to capture litter vs buying an expensive enclosure.

As seen in video:
Sifting Litter Box (Arm and Hammer): https://amzn.to/3OLwHNV
Pine Litter (World's Best): https://amzn.to/3SjSeTb
Corn Litter (Feline Pine): https://amzn.to/3TVZfKT
Litter Scooper (WePet): https://amzn.to/3HlnqLr
Litter Mat (Amazon Basics): https://amzn.to/3Sh5XKc
Top Entry Litter Box (IRIS): https://amzn.to/3Hj98e8
Step Trash Can (mDesign): https://amzn.to/3RTLHNz