Review on Versatile Food Slicer: Efficiently Cut Tomatoes, Grapes, Olives, Chicken, Shrimp, Strawberries, Salads. Includes Non-Slip Gadget Holder for Effortless Slicing of Various Foods by Michelle Armstrong

Has a raised edge to guide the knife but I think it was just to keep things from rolling out. Great for halving tomatoes and chicken breasts, but make sure you have a sharp knife when slicing tomatoes. For chicken breasts, this is way better than just a knife. I would suggest improving the design of the product so that one side has a bottom edge that matches the existing one and one side has a higher edge for thicker items like chicken breasts to avoid uneven top and bottom halves. I have never managed to make a clean slice of chicken with this product.