Requirements:

Bottle caps

Empty coke tin

procedure:

Cut empty coke tin and separate two portions one is bottle cap size and another one an inch width straight portion

Step 1: Making Inner Part of the Whistle

Take the straight portion and at the edge place the smaller portion and twist the edges of smaller portion and the roll it back in a circular way

Step 2: Making Covering Portion of Whistle

Take two bottle caps and make a small gap as shown in the figure and the by hot glue stick the inner portion between two caps

finally make some gap near the blowing section with any pointed object finally our whistle is ready