Omega Paw Roll 'n Clean Self Cleaning Litter Box, Brown, Large
We used this for about a month, but it didn't work with our preferred brand of litter. Cleaned and sterilized.
This is a non-electric self-cleaning box. You roll it onto its side to clean out the clumps, so it has to be used with a clumping litter. The clumps end up in the bin, which you just empty into the garbage (or use a liner bag of some type).
Easy pick up from near the 75th Ave E/F subway station. Asking $25 OBO.