These are Possibly the Best and Highest Quality 4-Wall and a Lid Compost Bins on the Market. Made from 5 mm Thick Recycled Plastic, These are Much Stronger Than Similar Resin Units.Walls Include Unique "Active" Aeration System - Which Provides Superior Air Flow - Increase Microbial Action. The Juwel Composter is Rodent Resistant with Hinging Lid and Sliding "Lock" to Keep Animals Out. Walls are Held Together with "Large" and Heavy Duty Sliding "Clips" - Easy to Disassemble. There are Two Doors to Remove Compost.