With 430 lumens, the Duo Z2 has extremely high luminosity. It's waterproof for ca. 30 minutes in fresh water up to a depth of 1 metre, battery powered and extremely robust. This makes it ideal for demanding outdoor sports (speleology, orienteering, biking, etc.) The Duo Z2 is equipped with Petzl's patented Face2Face anti-glare function so as not to dazzle and blind others, which makes group movement easier. Five light modes are available to the user as required. These range from a wide cone with low and long luminosity to boost mode for short-term maximum luminosity of 430 lumens. The lamp has a large, ergonomic switch that is easy to operate even when wearing gloves. An electronic lock protects against unintentional switching on during transport and when the light is not in use. The battery housing carried on the back of the head creates a balanced weight distribution. If the battery is almost empty after a long tour, the Duo S automatically switches to reserve mode.
With Constant Lighting headlamps, the luminous intensity does not change during the specified light duration. This luminous intensity is below the maximum value when the lamp is switched on. At the end of the light duration, the lamp automatically switches to reserve mode with reduced luminosity.