Bottle Lifebuoy / Lifebuoy

There are many water and drink bottles filled with our world. How to recycle the water and drink bottles? They can be made into a lifebuoy!
Bottle Lifebuoy consists of two parts, one part is the bottles, the other part is hollow structure of the rubber rings which can put the bottles twisted around. Each port is independent of the closed, even if one port appears slack would not affect the normal work. There are 20 bottles fixed to it, to ensure that can generate enough buoyancy.