Special lightweight silicone in this two layer design provides the benefits of moldable silicone, without the heavy feeling. Less pressure, on your chest and your shoulder, is the key to this form. The back layer uses a revolutionary Shapes2U^TM Technology from Amoena®, a new material that snugly conforms to the unique shape of your chest wall when you put it on and gently holds that shape until you take it off. The asymmetric, average-fit shape provides some extension for moderate surgeries, while the lighter weight addresses the needs of those with back or shoulder weakness. Perfect fit and total comfort!