This pair of replacement parts, specially designed for the QC45 and QC SE models, perfectly replaces worn or "flattened" ear cushions, which are key to the headphones' performance. Made from soft foam and covered with premium leatherette, they restore the perfect seal around the ear. This fit is essential for the Active Noise Cancelling technology to operate at its maximum potential, allowing you to immerse yourself once again in your world without distractions. It is the smartest upgrade to make your headphones feel like new again and continue enjoying the unparalleled tranquility that only Bose can offer.