Clinique iD is a revolutionary custom-blend hydrator that gives you the power to hydrate and treat your way. Custom-Blend Chemistry Technology™ isolates the concentrated actives in the cartridge from the base—delivers optimized results with every pump by freshly combining the precise dose of concentrated actives and base for the ultimate customized experience. International patent-pending package. Just pick your hydration base, insert your cartridge to treat your main skin concern and you're done. In 15 combinations. Customize, don't compromise. Notice some extra space in your hydration base? That allows for the addition of the active cartridge concentrate.