Instruct those entering explosion-prone environments to refrain from all use of naked lights. An explosion is illustrated, and a struck through match is also depicted. Text reads, “Explosive” and “No naked lights” Plastic construction. Manufactured by Jalite in the UK. Glows in the dark. Easy to adhere to most surfaces using sticky pads, double-sided tape or other common adhesive product. Measures 100mm x 150mm.