EnduroShield is an Easy Clean surface treatment for glass that cuts cleaning time by up to 90%. A single application lasts beyond 3 years. Suitable for all indoor and outdoor glass surfaces including new or existing shower doors, mirrors, windows, doors, railings and backsplashes. Application is simple: clean the surface with the included EnduroClean pre cleaner (and fine steel wool for removing stubborn build-up on existing shower doors), then spray and wipe the EnduroShield liquid into the surface. Thats it. Full instructions inside kit. EnduroShield not only creates an Easy Clean surface, but repels hard water, soap scum and grime, to keep the glass cleaner for longer between cleans. Doing away with the need for harsh, expensive and abrasive cleaners, investing in EnduroShield provides hassle free cleaning for as little as 83c per month. Kit cleans and treats up to 40 sq. ft. of glass or equivalent of the inside of one average shower enclosure.