Please note: This item requires a compatible Clinique iD Base to use. A revolution in skincare technology; the Clinique iD is a unique two part treatment that allows you to mix and match, combining this cartridge with a compatible Clinique iD base, creating a treatment tailored to your skin's needs. Custom-Blend Chemistry Technology ensures that the active ingredients of both the base and the cartridge are delivered to the skin with every pump. Ingredient potency is maintained. The Active Cartridge Concentrate for Uneven Skin Texture supports the skin by reducing the appearance of pores. In addition it provides AHAs which renew the skin’s texture. To use: Insert cartridge into a Clinique iD base making sure the cartridge is held firmly in place. Apply mornings and/or evenings to the cleansed face.