The Napier Pro 9 Noise Cancelling ear defenders feature a patented noise cancelling technology that works without batteries, electronics, valves, or any moving parts! The unique patented sound chamber technology, directs damaging sounds away from the ear canal, where they are dampened, refracted and cancelled. The effect is amazingly clear low level sounds such as speech, but with highly efficient protection from damaging noise levels such as gunfire with over 32 Decibels of noise reduction. The soft comfortable and replaceable ear cuffs seal at the ear but are not inserted into the ear canal, which is ideal for those who do not like having traditional ear plugs inserted. The lightweight unit is barely noticeable when worn and can therefore be used for long periods without discomfort, vitally important when used by instructors, students, beaters, trappers etc. Normal conversation is possible whilst wearing the Pro 9 and it is slim with no profile below the ear, making it vastly more suited to shotgun mounting that any type of ear muff. The unit is remarkably light at just 40 Grams 1.7 ounces and it can be folded and carried in a shirt pocket. It is also completely weatherproof.