i have just fitted a custom duo spot module to my petzl duo,( i know how much they are hated on here but i have abused mine for a good few years with no problems). the module is a cree q5 led encased in a shaped aluminium sheet, which acts as a heat sink and gives it a factory look. fitting took 2 minutes, and the light gives a nice looking spot at a claimed 110 lumens. both the led module and the way it fits in the halogen bulb holder look very similar to the bisun led spot, but the aluminium sheet makes it look a lot better. it might be a week or two before i can get it underground, but first impresions are good.