The SideSwipe series of beater heads are made to fit KitchenAid stand mixers. They have silicone fins on the outside edges of the blade, and they work great to make sure your mixer is picking up all of the icing or batter from the edges of your mixer bowl. I find this really helpful, especially when I'm using food coloring in a batter or icing - I don't want to have to keep stopping the mixer just to scrape down the sides of the bowl. There are several sizes of SideSwipes, so make sure you're buying the one that's made to fit your KitchenAid mixer bowl. Amazon has the entire collection, and they cost between $25 and $30. I can't live without this accessory! It's the only one I've ever purchased for my KitchenAid stand mixer.
I love this attachment. Finally no more stopping and cleaning the sides and bottom of bowl a zillion times in order to make sure my mix is totally combined. I used this while making my whoopie pies and I just let it go thinking okay I am going to have to wipe a little bit but no, this mixed everything beautifully. Nothing stuck to the sides or bottom of bowl. This is the best attachment ever invented for the kitchenaid. The only con, and I can live with it, is that the mix is a bit of a pain to clear off the sideswipe itself. It just takes a little longer to clear off but the mix is still all combined. So easy to wash. I washed by hand as I am not a big fan of putting these in the dishwasher. Cleans quick and easy.