These collapse/open -- popping in/out -- fast and easy. I like the carabiner for easy attachment to a water bottle, backpack, or leash handle. These were smaller than I imagined, but that still works for my medium breed dog (40lb female husky). I need to refill water often but that ensures she always has fresh, clean water to drink. Less to get dirty (especially at campsite) and tip over from a human or canine bumping into it. Ideally a bigger bowl would be better for my dog, but my family plansSee full review