The Etymotic ER38-14C are interchangeable memory foam ear tips for Etymotic ER4SR and ER4XR earphones. The package includes 3 pairs of L sized yellow ear tips. Other compatible Etymotic models: HF series, MC series, ERMK-5 Isolator, EtyKids, HD5 Safety, MusicPro, Gunsport Pro, HD15-High Definition Electronic Earplugs, EB-15 BlastPlug, etyBLU2, The BEAN, and Home Hearing Test