Crosswordiee.com

% replaces any number of letters (la% - lake, lamp)_ replaces one letter (ca_ - car, cat)

Crossword clues for Certain layers 4 letters:

HENS: Certain layers
III: MPEG-2 Audio Layer _____ (certain file type, formally)
OZONE: Certain layer
HEN: Certain layer
WAFER: Certain snack layer
OZONE: Certain atmospheric layer