303 is THE LEADER in UV Screening Technology. This is the hot tub cover cleaner to use! 303 does not contain, silicone oils, waxes, glycerine or petroleum distillates. This means that 303 leaves a 'like-new', non-oily, anti-static finish that repels dust and dirt. 303 bonds into the vinyl surface to block the sun's UV rays and guard against cracking and fading and, with regular use, 303 will provide 100% protection against UV fading. 303 was originally developed for aerospace and aviation applications and can be used to clean and protect virtually any vinyl, leather, rubber, plastic, fibreglass or metal surface. Try it on your patio furniture and you won't be disappointed. DO NOT use this product on the hot tub surface.