Hood-in-hood design draws excess gas into vacuum, reducing ambient N2O. Clear outer hood shows patient 'breathing through nose' (fogging appears in hood). Soft inner hood creates desirable nasal/facial seal and seal can be seen through clear outer hood. Low profile expands clinical field of view, provides easier access to the mouth and keeps patients from adjusting hood to see operatory TV monitor and staff activities. Single-use minimises cross-contamination and saves staff time. Latex-free. Individually wrapped.