The Chisel Shadow Brush is used for eye shadow application and blending.   I use a separate one for light colors, medium shades and dark smokey colors.  They are priced so you can have a few brushes on hand.   It's a long handle brush, 7.5 inches long.  It's a very soft, natural bristle brush that’s gentle on the eyes.  It easily applies the color to your eyelids. 

 Always blend the the eyeshadow well so there's no obvious demarcation and so it looks soft and flattering to the eye.  ~ Jill