Magicshine Accessories, Extension Cable, Split Cables, Adapter Cables 900 Series, 800 Series and Eagle Series Bike Lights & Batteries 39.5in Extension cable MJ-6016 is compatible with all Magicshine bike lights with round plug. MJ-900 helmet light, MJ-902, MJ-906. As well as MJ-900B, 902B 906B Bluetooth bike lights. Extends the distance between the headlight and external battery which can now be stored inside your backpack. Massively reducing the weight your helmet carries. Tightly fitting connectors provide excellent weatherproofing