This had a constraint that it had to be an environmentally friendly design. The pepper spray 
unit developed consisted of a sweat band, dish washing sponge, a sock and a pepper spray. 
It was aimed towards regular joggers in deserted parts of Brooklyn where one needed to 
have  ready-to-use self defence. 
The used dish washing sponge is recycled, so is the one sock which doesn't have a pair. 
The whole unit can be assembled in 10 minutes which will encourage people to make it.