delivered to all passengers at the same time. A safety demonstration typically covers all these aspects, not necessarily in this order: the brace position, which must be adopted on hearing the "Brace, Brace" command during an emergency landing (sometimes called the safety position; this is not required in the United States and certain other countries and is mostly included in European regions) the use of the seat belt; most airlines recommend or require that passengers keep their seat belt fastened at all times in case of unexpected turbulence the location and use of the emergency exits, evacuation slides and emergency floor level lighting a diagram or description of the location of exits on that particular aircraft, or that they are being pointed out by crew and are described in the safety card a reminder that all passengers should locate (and sometimes count the number of rows to) their nearest exit, which may be behind them the requirements for sitting in an emergency exit row (varies by country and airline); in some countries (including the United States) it must also be stated that exit row passengers may be required to assist the crew in an evacuation that all passengers must leave all carry-on bags behind during an evacuation some demonstrations also mention that high heeled shoes and/or any sharp objects must be removed (this is to ensure that evacuation slides are not punctured) the use of the oxygen mask (not included on some turboprops which do not fly high enough to need supplemental oxygen in a decompression emergency) with associated reminders: that the passenger should always fit his or her own mask on before helping children, the disabled, or any persons requiring assistance that even though oxygen will be flowing to the mask, the plastic bag may not inflate (required in the United States after a woman fatally removed her mask thinking it was not working); some planes such as the Boeing 787 or Boeing 777-300ER do not include plastic bags in the oxygen masks. if applicable to the aircraft in question, that the passenger must pull down on a strap to retrieve the mask this part of the safety demonstration is sometimes technically permitted to be done after take-off, since it is not applicable while the aircraft is at low altitude the location and use of the life vests, life rafts and other flotation devices, like floatable seat cushions (not