Crafted from premium solid aluminum material, this portable keychain whistle is sturdy, rust-resistant and long lasting. The double-hole structure ensures stable, far-reaching sound output. It comes with a sturdy metal keychain for convenient carry anywhere you go. Simple and sleek appearance supports custom logo engraving to meet promotional, gift and team use needs. Perfect for camping, travelling, pet training, referee use, survival emergency and daily outdoor adventures. Multiple fresh color selections are offered for your choice.