The Petzl Bike Adapt is a great little tool for attaching your headlamp to either your handlebars or seatpost. Useful if your main lights run out or if you just want to make the best use of headlamp. Works with the following petzl headlamps Petzl TIKKINA®, TIKKA®, TIKKA® CORE, ACTIK® or ACTIK® CORE.