The left box is full of the compost that we pulled from the old composter. The right box is ready to be filled. The lids open independently of one another, so you can access only the bin you need to. The idea is that one bin is for active compost (the one we will continue adding things to) and the other is for finishing compost, which we will prepare for use in the spring. We will stop adding material to the left box at the end of August, but will continue turning it to ensure adequate breakdown of material in time for spring planting.