Ear Parts Erasers Set 5 Pieces, Audiologist Hearing Set The Ear Eraser set include five key images and shapes of the ear outer ear, ear structure, cochlea, ossicular chain and brain. The package includes a quick reference card of the ear structure. Makes a great gift for a colleague, a teaching aid and as erasers too! Approximately 1 1/2" x 1 1/2". Package includes five total erasers and one quick reference card.