What is the maximum aperture of the lens(es) with a focal length of 20mm?
CREATE TABLE table_79371 (
    "Brand" text,
    "Product Name" text,
    "Focal Length" text,
    "35mm EFL and equivalent aperture" text,
    "Max. aperture" text
)
SELECT "Max. aperture" FROM table_79371 WHERE "Focal Length" = '20mm'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is the maximum aperture of the lens(es) with a focal length of 20mm? ### Input: CREATE TABLE table_79371 (
    "Brand" text,
    "Product Name" text,
    "Focal Length" text,
    "35mm EFL and equivalent aperture" text,
    "Max. aperture" text
) ### Response: SELECT "Max. aperture" FROM table_79371 WHERE "Focal Length" = '20mm'