If you prefer the Shure foam tips over the silicons, you can get comparable tips from Comply or Westone. I have tried all three brands, and found the sizes to be comparable. In other words, if you are using a medium Shure foam, you will probably be OK with a medium Comply or Westone Tru-Fit. There is a Westone Tru-Fit foam sampler available on Amazon if you want to try different sizes. I haven't seen a comparable multiple size pack from Comply. As I said, I have used foam tips, but have since switched to the Westone long Star silicon tips with my SE215's and 535's. I find them to have as good a seal as the foams, good isolation, and they are easier to get in and out of my ears. I was using the medium foams and I went to the medium Star tips (red)...perfect fit. Amazon also sells the Westone Star sampler if you want to experiment. In my opinion the Westone Star silicons are more flexible and more comfortable than the silicon tips provided by Shure. Amazon also sells single sizes of the Westone Tru-Fit and Star tips in multiple packs...5 pairs per pack I believe. Amazon also sells replacement Shure tips.