Everybody knows the slap wrap type reflectors? Good. Here's a high quality specimen (EN 13356, CE) that should last a long while unless you lose it. That's why you should get one for every jacket pocket.

Pull it straight and slap on your hand or other suitably thick member and it will wrap around it. Kinky, eh? At least handy. Also very good quality and will last a lot longer in the dark than you would without one. Practically the only normal method to render it unusable is to lose it. So, keep one of these in all of your jackets.

Made in the EU.