Up for sale is a pack of custom-like, deep-inserting, and comfortable ProGuard EarPortz Earphone Tips. The XL fits me, so I am selling the remaining of trial pack (S, M, L). The EarPortz Eartips will fit the following earphones: Shure E3c, E4c, E5c, E3g, E4g, E500, i3c, i4c, SCL3, SCL4, SCL5, SE 110, SE 115, SE 210, SE 215, SE 310, SE 315, SE 420, SE 425, SE 530, SE 535; Westone UM-1, UM-2, UM-3X, Westone 1, 2, 3, 4; Future Sonics Atrio Series (all); Ultimate Ears Super Fi 3 Studio, Super.Fi 5 Pro, Super.Fi 5 EB; Ultimate Ears Triple Fi 10 Pro; Comply NR-1 CM mobile phone earset, NR-1 CS mobile phone earset, NR-1 earphones and NR-10 earphones. Etymotic Research ER-4B, ER-4P, ER-4S, Ety-8; and Or any phones with stems from 2 to 5mm in diameter. More information about these tips: http://www.head-fi.org/t/570022/earportz-tips-for-iems And here's some glowing comment from Ericp10: ericp10 Been listening to the W4 for the last couple of days . . . . I will have to agree with you that the W4 is one outstanding IEM paired with the right DAC and amp. Also with the right tips (I use the very deep inserting Earportz, which gives me a custom-like fit and seal). The tips I use really brings out the sub-bass in the W4, and I've said before I don't think there is a better universal IEM that I've heard for instrument separation.