Halo is a handy light-writing tool, preserving the techniques and gestures that graffiti artists use with spray cans. It is possible to change the color and the brightness of the led to change the graffiti’s styles. If the light doesn’t have enough battery, users simply have to shake it to have energy again. Same material used as sweatshoppe (led).
http://www.aissalogerot.com/#/projects/halo/ (Nice artist also his other projects)