The Nextorch K21 is a powerful little pocket light powered by a single AA battery. For its size it has an impressive 160 lumen output and it will clip to a cap peak or stick to a magnetic surface for hands free operation. The on off operation is activated with a simple turn of the head which will also access two lower power modes. It is made from 6061-T6 Aluminium with a bang up to date Cree XPG3-S4 LED so will resist knocks and not let you down.