This membrane switch is applied to salt water spa systems. The silver printing circuit combines with overlay and window (matte or clear). Any color can be printed including gradient color printing with overlay switches (embossing or not). The IP degree is 65 to 68, and the product is ISO9001, ROHS, MSDS, PFOS, and PFOA certified. The switches are durable and waterproof, and the lifetime of the product equates to 1,000,000 times of usage. The metal dome is put inside in order to enhance the sense of touch.