Petzl tikka rxp headlamp the petzl tikka rxp headlamp is perfect for dynamic activities thanks to its reactive lighting which automatically adjusts the output and light beam to match your environment thanks to a built in light sensor while a simple switch to the side changes the light from reactive to constant light this petzl headlamp also benefits from a lock function that prevents the light from being turned on accidently while in transit or storage teamed with an easy to adjust headband