The EU Directive allows "enriched" or "furnished" cages to be used. Under the directive, enriched cages must be at least 45 cm high and must provide each hen with at least 750 cm2 of space; 600 cm2 of this must be "usable area" – the other 150 cm2 is for a nest-box. The cage must also contain litter, perches and "claw-shortening devices". Some animal welfare organisations, such as Compassion in World Farming, have criticised this move, calling for enriched cages to be prohibited as they believe they provide no significant or worthwhile welfare benefits compared with conventional battery cages.