This model simulates an old-style 3-reel jackpot machine. You insert a coin by pressing the "Insert Coin" button and upon doing so, the "Spent" display updates to show you how much you've spent so far. Then you click on the "Pull" button to make the 3 reels turn independently and at random speed. The images on the reels change as they spin. If you slow the reel speed down (using the slider), you can see that the reels start out spinning fast and then slow down over time until they finally stop. When they do, the light above the machine will show red or green, indicating whether or not you won. A jackpot occurs when you get 3 of the same image. In this case, the light will display green and you will be notified that you won the jackpot!