Probably the most familiar symbol that denotes if an item can be recycled is the Mobius loop. The symbol intended for use only on goods that are capable of being recycled if a facility exists, but it has no precise meaning and is often misused (closed-loop system). The Mobius loop with a percentage sign indicates that the product contains the given percentage of recycled content which is more meaningful than the empty loop.
The only known product is Glass. Glass recycling is a perpetual form of recycling. Unlike some other recycled products, a recycled bottle transferred into other glass bottles; this process can go on endlessly with no loss in quality or purity. Glass is 100% recyclable. See Glass recycling.