"Safety of Life at Sea"
The original and best retroreflective tape from 3M. This is the stuff the Coast Guard uses for life vests and the DOT for signs and cones. I know this doesn't have much to do with Cargobikes (well, actually it does if you're hauling kids around in the dark!), but this stuff is great. Essentially zero weight, no rattle-factor and incredible durability and visibility. Use on mud flaps, fenders, forks, etc. for extra visibility. If you crash on a dark, rainy night this may be the only thing an approaching motorist might see... Much better than the crap that most bike shops and hardware stores sell. Get some for your loved ones and stuff it in their Christmas stocking this year.