We were impressed by the design of these modular compost bins; they incorporate a host of features for keen composters! The duvet is made from woven polypropylene, plastic bubble wrap with brass eyelets. ? Can be assembled in minutes - no nails, screws or holes to dig. ? Slide-out panels on all sides for easy access. ? 573 litres (20 cu.ft.) capacity per module. ? Wood provides good insulation, while allowing the compost to ?breathe?. ? Timber is from managed forests, and treated with non-toxic preservative. You can start with one, but we?d recommend two (Bin and Module) to get the benefit of being able to easily turn the heap from one bin to the other. And when you?ve seen how well they work, you can add extra modules in the future. Size 91cm (3\') square x 68cm (27) high. Wooden Compost Bin pack (base unit) contains - 4 posts and 20 panels. Wooden Compost Module contains - 2 posts and 15 panels -(using the existing base unit this part extends the Modular Wooden Compost Bin) . PLEASE NOTE: The module is only compatible with other modules and compost bins of the same sort purchased from 2019. The duvet (available to purchase separately) is made from woven polypropylene, pastic bubble wrap with brass eyelets.