The Led Lenser ZL7784 Lithium-ion battery pack is a spare or replacement battery, which fits all Led Lenser SEO7R model rechargeable headlamps.This battery is also suitable for use in all Led Lenser SEO3 & SEO5 model headlamps (However) an additional charging power adaptor with cable part number ZL0389 is needed to charge the battery pack separately out of the headlamp when used in conjunction with these models