The inner labia are the hairless, wrinkled, often darkly pigmented lobes of skin which fringe the vagina.

They come in a variety of sizes and shapes: they can be practically nonexistent or long and prominent --and no matter what size they are, they are never the same on each side. It is common for them to be different sizes. Inner labia come in many shades; pale peach, mauve, shades of pink, burgundy, or dark chocolate, and the color may deepen after childbirth. The inner lips are richly endowed with nerve endings, and the clitoral hood ¨C where they meet at the top of the vaginal opening -- is analogous to the foreskin of the penis.

Some women enjoy stimulation of the inner lips more than their clitoris.

Referrence:Inner Labia(Chinese Version)