BIG GREEN EGG DUAL FUNCTION TOP M-L-XL EGG - The multi-variable daisy wheel design allows for precise temperature control – rotate the larger opening for higher or lower temperatures, and simply adjust the smaller openings to fine-tune the cooking temperature as desired. For best results, open fully when lighting the EGG. Cast iron. Do not scrub. Store inside EGG when not in use, cover dome opening with ceramic cap.