The kit includes an adjustable, machine-washable harness, a Silk Small and Silk Medium, and a bullet vibrator that fits into a small pocket in the harness. There's also an extra o-ring, so that the harness can be used with toys of different diameter. Made from a unique formula of 100% Ultra-Premium Silicone. The harness fits up to 60 in. hips. The Silk Small insertable length is 4.25 in., 0.8 in. diameter. The Silk Medium insertable length is 5.5 in., 1 in. diameter.