The shape and size were odd but I was able to figure it out using two pockets to store my stuff. What I found unacceptable was the instant transfer of temperature from the packaged goods to the outside. So I put the things in double bags. Another transfer of temperature through the heater. Then he added insulation to the walls of the box. I doubt my efforts have helped. And I just hope the fast delivery doesn't spoil the food. Next time I'll buy a soft insulated fridge like insulated lunch bag for kids. Can work better and can't work less effectively. I can't imagine what the true or original purpose of these bags was or is.