They sell optional large bases, which cost $15 extra, and that is an option I selected. It is very stable.
Phaewryn http://ucat.us Adopt a New England FIV+ cat: http://ucat.us/FIVadopt.html Special Needs Cat Links (and feline info library): http://ucat.us/domesticcatlinks.html Declawing Creates SUFFERING, Please don't declaw! http://www.pawproject.com/kona.html

