My son wanted something to give him some peace of mind when he goes to his friends on his new bike. I saw this 3-pack set and thought it was a good deal.To use this product, all you have to do is wrap the chain around the bike and a post. There are 3 chains and 3 keys; Any of the keys will work with the three chains so it doesn't matter if you accidentally mixed them up. The chains are wrapped in plastic hose tubes in 3 different colors. The hoses cover the bare chains to prevent scratching the paint of his new bike.One thing to bear in mind. This is not a foolproof way of protecting your bike. Any determined thief who has the right tools will have no problem taking your bike. But if he has a choice and see your bike with a chain on it, he will probably pass on to the next bike for an easier ride. Also, most of the times, it just another kid who wants to swipe your bike for a joy ride in the neighborhood and leave it in middle of the park.