Did you get the whole blade as a replacement or just a refill?? I prefer to get the whole blade, not ever having much luck with the cheapo refills. I know for a fact that WalMart blades are SUPPOSED to fit but they don't. I had to go to NAPA to get the "proper" ones. The hook on the wiper arm fits over a pin on the blade and then has a locking device that snaps into place to hold it from moving and falling off. Hope this helps.

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)