PACKAGE INCLUDES 10 Black Left Medium EAR MOLDS We are here to provide you with the best buying experience. While the Flexible Open Ear Insert fits entirely inside the ear, its open frame design still allows the user to hear ambient noise. The ultra flexible material comfortably conforms to the shape of the users ear, even permitting telephone and headset use while wearing the Flexible Open Ear Insert. Sizing Specs Small: Concha bowl height 15⁄16 to 1 inch. Medium: Concha bowl height 1 inch. Large: Concha bowl height 1 and 1⁄16 to 1 and 3⁄16 of an inch. Used by Police and security agencies all over the USA