From SpongePedia, the First SpongeBob Wiki.
The slide whistle is colored blue. It has a mouthpiece at the end which lets one play it. With a rod that lets the player change the tempo the rod is colored Gray
 Pranks Done with the Whistle
- Fooling a muscular fish into thinking another fish was falling in love with his girlfriend.
- Pretending that someone was entering Barg'n Mart.
- Mimicking sounds
- The slide whistle is based on a real instrument.
- It can also act like a dog whistle.
- Everybody at the hospital seems to like the slide whistle.