The CDC Dry Fly Hare Ears is an effective fly in flies spawning and even their absence to fish the posts.
It takes again two classics of Fly-Tying that are:
The CDC wing that provides low floatation and natural aspect
The body dubbing hare for its mimicry and its slightly gruff appearance that suggests the emerger time
This fly will give you a low or very low floatation if you do not grease the body, do not grease the wing.