Viper Fang 20 Battery Powered Walk Behind Scrubber. This 20 inch floor scrubber is the workhorse of the battery running auto floor scrubbing machines. A comfortable 20 inch cleaning path and easy to operate auto scrubber will make daily floor cleaning a simple process. VIPER automatic floor scrubbers are built to tackle everything from the small area floor cleaning, warehouse floor cleaning, store aisle floor cleaning and large area floor scrubbing.