These adapters help convert 8mm diameter products to 9mm and vice versa.  This is useful if you want to use your 9mm BFG Fusion tip on one of your 8mm stems (9mm Tip to 8mm Stem Adapter).  Alternatively you can use your 8mm Dynavap / Thermal Accumulator / Tempest tip on your 9mm stem adapter (8mm Tip to 9mm Stem Adapter).

You are paying for a single stainless steel adapter.  All stems and tips are sold separately.  If they are pictured here they are for demonstration purposes only and not included in the sale.