I did not care much for both of the tri-flange tips included with the Etymotic Research HF5 Portable In-Ear Earphones (Cobalt). They had to be inserted pretty deeply to get a good seal to get the most out of the HF5. After extended listening, they began to bother me. They didn't hurt, they just weren't as comfortable as I'd like. Based on recommendations from an audio forum, I decided to give the Klipsch LG CLR Large Size Replacement Ear Tip - 4 Pack - Clear a try. These were the perfect solution for me. They provided a very good seal without deep insertion. Also, in my opinion, they opened up the soundstage a bit more than with the stock tri-flanges. The seal let me hear consistently better bass, which was hit or miss with the stock tips unless you stuck them in way deep. I did not hear any degradation in the sound quality but rather improved clarity in the entire spectrum. For me, this is a great match, sound- and comfort-wise. Just for comparison, these large tips replaced the medium (gray) stock tips of the HF5.