Gutter Zap cleans black streaks off gutters caused by electrostatic bonding. Simply wet down the gutter, spray on Gutter Zap with your favorite chemical injector and rinse off with garden hose pressure. Gutter Zap will clean gutter quickly and easily and it will not harm vegetation or painted surfaces. Purchase some Gutter Zap for yourself and watch those zebra stripes dissapear! This gutter cleaner will remove black marks from your gutters and make them look brand new!