We usually tell customers to use the same size Comply Foam Tip as you would with silicone tips.Size will make a difference in retention and noise reduction. However, sinceour foam tips are compressible to insert and then expand in your ear, we have found that the medium size fits most users comfortably. If you are still unsure, consider buying the Mixed Pack (includes a pair of each S, M and L).This also can give you some options – for example, some customers use multiple sizes for different purposes;  such as small for casual listening at home and medium for additional noise isolation when on a flight, etc.

 
Make sure you use the Comply™ Fit Finder to verify what tips are compatible with your device.