The new Mutation X v4 now has diamond airflow holes to create a swirling effect within the atomizer and a redesigned, wider top cap. The latest version of this popular atomizer by Indulgence also has two new large bottom feed airholes that flow directly into the coil, and it still features the famous 18 adjustable air holes in the sleeve,. The Indulgence Mutation X v4 is made with 304 stainless steel or copper depending on finish.