What are the characteristics of the top -grade stone slab pigeons

The stone slab pigeons are gray -colored pigeons. The color of the feathers is blue -butt, and there are grouper, which is some rainy spots on the stone.The pure variety is generally blue and blue. After the shell is broken, the mouth is white. There is a black circle with the tip of the mouth.It is worth mentioning that because this kind of pigeon can continue to be inherited for many years, the descendants are very good, whether it is planted or competing.