What does the cryptic crossword clue "Double Gloucester in germ-free packs (6)" mean?

The definition is "Double". The wordplay uses a hidden word. Hidden in "double gloucesteR IN GERm-free packs" The answer is RINGER.

Double Gloucester in germ-free packs (6)

Times Cryptic #28714 | 8 Down | 2023-09-21 flower