This set includes 2 oxygen in use warning signs designed to enhance safety in areas where oxygen is stored or used. Each sign measures 5.9 inches in length and 3.9 inches in width, featuring a classic red, white, and black color scheme that clearly communicates the danger of smoking or open flames in oxygen-rich environments. Constructed from high-quality vinyl material, these signs offer superior durability compared to standard stickers, with a substantial thickness that provides flexibility while resisting breakage. The waterproof material ensures long-lasting performance without rusting, making them suitable for extended use. The signs feature a delicate matte finish and come with self-adhesive backing for straightforward installation on clean, smooth surfaces such as doors, windows, and walls. These warning signs are particularly appropriate for hospital storage rooms, industrial oxygen production and storage facilities, laboratories, aviation oxygen system areas, and fire equipment zones where oxygen is present. Installation is simple - just remove the backing tape and press firmly onto the desired surface.