Crystal Clear

Adjective:

1. Transmitting Light; Able to be seen through with clarity

(Usage: Crystal clear skies)

    2. (of Language) transparently clear; easily understandable
(Usage: A crystal clear explanation)

Synonyms:

1. Crystalline
2. Limpid
3. Lucid
4. Luculent
5. Pellucid
6. Perspicious
7. Transparent