A surgical mask is used inside the operating room or during other sterile procedure areas to protect the patient environment from contamination. Surgical masks have ties so that they can be adjusted for fit, and are tied over the top of a surgical or bouffant cap.
rockfall. 1  an act or instance of the falling of rock, as in a cave-in or an avalanche. 2  a mass of rocks that have fallen: to be trapped under a rockfall.
Rock crawling is a category of off-roading. Vehicles used for rock crawling are usually modified with different tires, suspension components that allow greater axle articulation, and changes in the differential gear ratio in order to obtain characteristics suitable for low speed operation for traversing obstacles.