Check the listing for details. Liberty Mountain Aluminum Emergency Whistle (Small, Black, 2-Pack). Condition: New. Listed at 8.12 USD. Lightweight aluminum construction. Black colorway. Aluminum construction is more durable than plastic and won't crack in cold temperatures. See also the Small Red (LIB0544-2), Green (LIB0542-2), Purple (LIB0543-2) and Large whistle options (LIB0550-2, LIB0551-2, LIB0552-2, LIB0553-2).