The outboard sides of the squeegees have cross hatch patterns on them that are supposed to "scrub." The videos on YouTube are interesting. I get such good mileage out of my OEM blade frames with silicone rubber inserts ordered from Malaysia or China on eBay I've been reluctant to try anything different. I'm past three years on the set of inserts I am using now. the Scrubblade is pretty good in concept, but I wondered if they were good in practice. The company has this nasty test in which the guy shoots live crickets at a windshield to make splatter - gross.