Size Chart(All Series):- L: Height 9mm, Outer width: 13.5mm. M: Height 9mm, Outer width: 12mm. S: Height: 9mm, Outer width: 11mm. Symbio has designed a ground-breaking hybrid ear tip with Silicone outer surface and Memory Foam inner filling. Enjoy the best of both worlds with this hybrid ear tip design that fits most IEM nozzles in the market. The Symbio hybrid ear tips are available in different nozzle diameters with different models including Symbio W, Symbio Wn, Symbio Wa, and Symbio W peel. You can choose the one appropriate for your IEMs. Hybrid Design With Both Silicone & Memory Foam Materials:- Some people find Silicone tips to be more comfortable, but the smooth custom-like fit of Memory Foam ear tips is unmatchable. In order to bring both worlds in a single pair of ear tips, Symbio has designed its premium W series of replacement ear tips. Symbio W:- Symbio W is the standard Ear tip with an inner diameter of 4.5mm. It is suitable with IEMs with an ear nozzle diameter of 4.5mm-6.5mm. Symbio Wn:- Symbio Wn is the same as the Symbio W with an inner diameter of 4.5mm. It is suitable with IEMs having a nozzle diameter of 4.5mm-6.5mm. It comes with adapters to connect it with narrow nozzle diameters with a stem diameter of 3-4mm. Symbio Wa:- Symbio Wa ear tips have an inner diameter of 4.5mm suitable for IEMs with 4.5mm-6.5mm ear nozzle diameter. It comes with adapters to connect narrow nozzle diameter IEMs with a stem diameter of 2mm-2.5mm.(Shure SE, Weston UM Pro, and more). One set contains three pairs of ear tips with 2 pairs of adapters. Symbio W Peel:- Symbio W Peel is a standard silicone ear tips without memory foam filling. It has an inner diameter of 4.5mm suitable for IEMs with 4.5mm-6.5mm ear nozzle diameter.