My Black Lab can't get enough Frisbee, she demands it at least twice a day.  Unlike the flying discs made specifically for dogs, these fly just like a real Frisbee (both in distance and flight pattern) yet have the soft rim so the dog"s mouth isn't injured when she catches it in mid-air.  The brightly colored rim makes them easy to find when my throwing gets too wild and they end up somewhere she can't get to.  The rim is squared off and ever so slightly raised above the actual disc which makes it easier for her to pick up if it lands flat on a slick or level surface.