Maximum Noise Isolation Seals ear canal from environmental distractions. Enjoy music without raising the volume to compensate for external noise. Superior Audio Experience Precise, optimal seal channels sound directly into the ear canal to transform your listening experience. Secure Fit Heat activated memory foam expands to unique ear canal shape, creating a custom, secure fit for amazing in-ear retention. WaxGuard™ Acoustically transparent filter to prevent wax and debris from entering the sound port. Keeps your earphone sound quality how you like it. T-500 Specifications HeightSmall / Medium / Large: 10.67 mm ± 0.65 mm (0.420" ± 0.025") Diameter at proximal end (end attaching to device)Small: 10.67 mm ± 0.50 mm (0.420" ± 0.020")Medium: 12.45 mm ± 0.50 mm (0.490" ± 0.020")Large: 13.97 mm ± 0.50 mm (0.550" ± 0.020") MaterialsPolyurethane foam, thermoplastic elastomer (all RoHS compliant) T-500 Earphone Compatibility Atomic Floyd, Audio Technica (IM Series), Harman Kardon, Jaybird, JBL, JH Audio, Sennheiser (IE6, IE7, IE8, IE80) T-400 Specifications HeightSmall / Medium / Large: 10.67 mm ± 0.65 mm (0.420" ± 0.025") Diameter at proximal end (end attaching to device)Small: 10.67 mm ± 0.50 mm (0.420" ± 0.020")Medium: 12.45 mm ± 0.50 mm (0.490" ± 0.020")Large: 13.97 mm ± 0.50 mm (0.550" ± 0.020") MaterialsPolyurethane foam, thermoplastic elastomer (all RoHS compliant) T-400 Earphone Compatibility AKG, Altec Lansing, Audio Technica (ANC, CK, CKF, CKL, CKM, CKN, CKP, CKS, CKW, CKX, CLR Series), Beats, Beyerdynamic, Bowers & Wilkins, Denon , Dunu, Hifiman, JVC, Razer, Sennheiser, Sony (EX,NC Series), Ultimate Ears, V-Moda T100 Specifications HeightSmall / Medium / Large: 10.67 mm ± 0.65 mm (0.420" ± 0.025") Diameter at proximal end (end attaching to device)Small: 10.67 mm ± 0.50 mm (0.420" ± 0.020")Medium: 12.45 mm ± 0.50 mm (0.490" ± 0.020")Large: 13.97 mm ± 0.50 mm (0.550" ± 0.020") MaterialsPolyurethane foam, thermoplastic elastomer (all RoHS compliant) T-100 Earphone Compatibility Shure,, Westone, Klipsch, Etymotic